Saturn's cloud belts generally move around the planet in a circular path, but one feature is slightly different. The planet's wandering, hexagon-shaped polar jet stream breaks the mold -- a reminder that surprises lurk everywhere in the solar system. This atmospheric feature was first observed by the Voyager mission in the early 1980s, and was dubbed "the hexagon." Cassini's visual and infrared mapping spectrometer was first to spy the hexagon during the mission, since it could see the feature's outline while the pole was still immersed in wintry darkness. The hexagon became visible to Cassini's imaging cameras as sunlight returned to the northern hemisphere. This view looks toward the northern hemisphere of Saturn -- in summer when this view was acquired -- from above 65 degrees north latitude. The image was taken with the Cassini spacecraft wide-angle camera on June 28, 2017 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 752 nanometers. The view was acquired at a distance of approximately 536,000 miles (862,000 kilometers) from Saturn. Image scale is 32 miles (52 kilometers) per pixel. The Cassini spacecraft ended its mission on Sept. 15, 2017. https://photojournal.jpl.nasa.gov/catalog/PIA21348

The Persistent Hexagon

Unveiling the Hexagon

Saturn North Pole Hot Spot and Hexagon

This frame from an infrared movie from NASA Cassini mission shows the churning of the curious six-sided jet stream at Saturn north pole known as the hexagon.

Saturn north polar hexagon basks in the Sun light now that spring has come to the northern hemisphere. Many smaller storms dot the north polar region and Saturn signature rings put in an appearance in the background.

This frame from a movie from NASA Cassini mission shows a polar projection of the curious six-sided jet stream at Saturn north pole known as the hexagon in the infrared.

This nighttime view of Saturn north pole clearly shows a bizarre six-sided hexagon feature encircling the entire north pole. This is one of the first clear images taken of the north polar region ever acquired from a unique polar perspective

In this annotated infrared image, six cyclones form a hexagonal pattern around a central cyclone at Jupiter's south pole. The image was generated from data collected on Nov. 4, 2019, by the Jovian Infrared Auroral Mapper (JIRAM) instrument aboard NASA's Juno mission during its 23rd science pass of the planet. The JIRAM instrument measures heat radiated from the planet at an infrared wavelength of around 5 microns. https://photojournal.jpl.nasa.gov/catalog/PIA23559

This image is located along the margin between Terra Cimmeria and Elysium Planitia. This boundary region is typified by tectonic fractures forming long, linear depressions. The crater in the lower half of the image has a hexagon shape rather than the normal circular outline. The regional surface/subsurface fracture system deflected the impact generated pressure waves along the tectonic network, causing the linear sides we see in the image. Meteor Crater in northern Arizona has a similar flat sided shape, in that case a square rather than a hexagon. The Arizona crater impacted into sandstone and limestone that had a right angle fracture system. Orbit Number: 78210 Latitude: -7.13006 Longitude: 147.811 Instrument: VIS Captured: 2019-08-02 02:56 https://photojournal.jpl.nasa.gov/catalog/PIA23448

This image from NASA Cassini, made possible only as Saturn north pole emerged from winter darkness, shows new details of a jet stream that follows a hexagon-shaped path and has long puzzled scientists.

This nighttime view of Saturn north pole reveals a dynamic, active planet at least 75 kilometers 47 miles below the normal cloud tops seen in visible light. Clearly revealed is the bizarre six-sided hexagon feature present at the north pole

Saturn hexagonal polar jet stream is the shining feature of almost every view of the north polar region of Saturn. The region, in shadow for the first part of NASA's Cassini mission, now enjoys full sunlight, which enables Cassini scientists to directly image it in reflected light. Although the sunlight falling on the north pole of Saturn is enough to allow us to image and study the region, it does not provide much warmth. In addition to being low in the sky (just like summer at Earth's poles), the sun is nearly ten times as distant from Saturn as from Earth. This results in the sunlight being only about 1 percent as intense as at our planet. This view looks toward Saturn from about 31 degrees above the ring plane. The image was taken with the Cassini spacecraft wide-angle camera on Jan. 22, 2017 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 939 nanometers. The view was obtained at a distance of approximately 560,000 miles (900,000 kilometers) from Saturn. Image scale is 33 miles (54 kilometers) per pixel. https://photojournal.jpl.nasa.gov/catalog/PIA21327

NASA's Space Optics Manufacturing Technology Center has been working to expand our view of the universe via sophisticated new telescopes. The Optics Center's goal is to develop low-cost, advanced space optics technologies for the NASA program in the 21st century, including the long-term goal of imaging Earth-like planets in distant solar systems. A segmented array of mirrors was designed by the Space Optics Manufacturing Technology Center for the solar concentrator test stand at the Marshall Space Flight Center (MSFC) for powering solar thermal propulsion engines. Each hexagon mirror has a spherical surface to approximate a parabolic concentrator when combined into the entire 18-foot diameter array. The aluminum mirrors were polished with a diamond turning machine that creates a glass-like reflective finish on metal. The precision fabrication machinery at the Space Optics Manufacturing Technology Center at MSFC can polish specialized optical elements to a world class quality of smoothness. This image shows optics physicist, Vince Huegele, examining one of the 144-segment hexagonal mirrors of the 18-foot diameter array at the MSFC solar concentrator test stand.

NASA's Space Optics Manufacturing Technology Center has been working to expand our view of the universe via sophisticated new telescopes. The Optics Center's goal is to develop low-cost, advanced space optics technologies for the NASA program in the 21st century, including the long-term goal of imaging Earth-like planets in distant solar systems. A segmented array of mirrors was designed by the Space Optics Manufacturing Technology Center for solar the concentrator test stand at the Marshall Space Flight Center (MSFC) for powering solar thermal propulsion engines. Each hexagon mirror has a spherical surface to approximate a parabolic concentrator when combined into the entire 18-foot diameter array. The aluminum mirrors were polished with a diamond turning machine, that creates a glass-like reflective finish on metal. The precision fabrication machinery at the Space Optics Manufacturing Technology Center at MSFC can polish specialized optical elements to a world class quality of smoothness. This image shows optics physicist, Vince Huegele, examining one of the 144-segment hexagonal mirrors of the 18-foot diameter array at the MSFC solar concentrator test stand.

These natural color views from NASA's Cassini spacecraft compare the appearance of Saturn's north-polar region in June 2013 and April 2017. In both views, Saturn's polar hexagon dominates the scene. The comparison shows how clearly the color of the region changed in the interval between the two views, which represents the latter half of Saturn's northern hemisphere spring. In 2013, the entire interior of the hexagon appeared blue. By 2017, most of the hexagon's interior was covered in yellowish haze, and only the center of the polar vortex retained the blue color. The seasonal arrival of the sun's ultraviolet light triggers the formation of photochemical aerosols, leading to haze formation. The general yellowing of the polar region is believed to be caused by smog particles produced by increasing solar radiation shining on the polar region as Saturn approached the northern summer solstice on May 24, 2017. Scientists are considering several ideas to explain why the center of the polar vortex remains blue while the rest of the polar region has turned yellow. One idea is that, because the atmosphere in the vortex's interior is the last place in the northern hemisphere to be exposed to spring and summer sunlight, smog particles have not yet changed the color of the region. A second explanation hypothesizes that the polar vortex may have an internal circulation similar to hurricanes on Earth. If the Saturnian polar vortex indeed has an analogous structure to terrestrial hurricanes, the circulation should be downward in the eye of the vortex. The downward circulation should keep the atmosphere clear of the photochemical smog particles, and may explain the blue color. Images captured with Cassini's wide-angle camera using red, green and blue spectral filters were combined to create these natural-color views. The 2013 view (left in the combined view), was captured on June 25, 2013, when the spacecraft was about 430,000 miles (700,000 kilometers) away from Saturn. The original versions of these images, as sent by the spacecraft, have a size of 512 by 512 pixels and an image scale of about 52 miles (80 kilometers) per pixel; the images have been mapped in polar stereographic projection to the resolution of approximately 16 miles (25 kilometers) per pixel. The second and third frames in the animation were taken approximately 130 and 260 minutes after the first image. The 2017 sequence (right in the combined view) was captured on April 25, 2017, just before Cassini made its first dive between Saturn and its rings. During the imaging sequence, the spacecraft's distance from the center of the planet changed from 450,000 miles (725,000 kilometers) to 143,000 miles (230,000 kilometers). The original versions of these images, as sent by the spacecraft, have a size of 512 by 512 pixels. The resolution of the original images changed from about 52 miles (80 kilometers) per pixel at the beginning to about 9 miles (14 kilometers) per pixel at the end. The images have been mapped in polar stereographic projection to the resolution of approximately 16 miles (25 kilometers) per pixel. The average interval between the frames in the movie sequence is 230 minutes. Corresponding animated movie sequences are available at https://photojournal.jpl.nasa.gov/catalog/PIA21611 https://photojournal.jpl.nasa.gov/catalog/PIA21611

Ground cemented by ice cover the high latitudes of Mars, much as they do on Earth's cold climates. A common landform that occurs in icy terrain are polygons as shown in this image from NASA's Mars Reconnaissance Orbiter (MRO). Polygonal patterns form by winter cooling and contraction cracking of the frozen ground. Over time these thin cracks develop and coalesce into a honeycomb network, with a few meters spacing between neighboring cracks. Shallow troughs mark the locations of the underground cracks, which are clearly visible form orbit. The map is projected here at a scale of 25 centimeters (9.8 inches) per pixel. [The original image scale is 30.2 centimeters (11.9 inches) per pixel (with 1 x 1 binning); objects on the order of 91 centimeters (35.8 inches) across are resolved.] North is up. https://photojournal.jpl.nasa.gov/catalog/PIA22180

NASA's SPHEREx mission will study the universe's early expansion, the history of galaxies, and the composition of planetary systems. This animation shows the preliminary design for the spacecraft, including hexagonal sun shields that will help keep the instruments cool. Movie available at https://photojournal.jpl.nasa.gov/catalog/PIA23869

Saturn winds race furiously around the planet, blowing at high speeds which form distinct belts and zones which encircle the planet pole, as well as its famous hexagon as seen in this image from NASA Cassini spacecraft.

NASA Cassini spacecraft takes full advantage of the sunlight to capture these amazing views of the north polar hexagon and myriad storms, large and small, that comprise the weather systems in the polar region.

The area within Saturn north polar hexagon is shown by NASA Cassini spacecraft to contain myriad storms of various sizes, not the least of which is the remarkable and imposing vortex situated over the planet north pole.

Saturn and its north polar hexagon dwarf Mimas as the moon peeks over the planet limb. Saturn A ring also makes an appearance on the far right. Mimas is 246 miles 396 kilometers across.

Nature is often more complex and wonderful than it first appears. For example, although it looks like a simple hexagon, this feature surrounding Saturn's north pole is really a manifestation of a meandering polar jet stream. Scientists are still working to understand more about its origin and behavior. For more on the hexagon, see PIA11682. This view looks toward the sunlit side of the rings from about 33 degrees above the ringplane. The image was taken in red light with the Cassini spacecraft wide-angle camera on July 24, 2013. The view was acquired at a distance of approximately 605,000 miles (973,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 19 degrees. Image scale is 36 miles (58 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA18287

To give some sense of the immense scale of cyclones arranged in a hexagonal pattern at Jupiter's south pole, an outline of the continental United States is superimposed over the central cyclone and an outline of Texas is superimposed over the newest cyclone. The hexagonal arrangement of the cyclones is large enough to dwarf the Earth. The JIRAM image was obtained during the 23rd science pass of the Juno spacecraft over Jupiter, on November 4, 2019. The JIRAM instrument measures heat radiated from the planet at an infrared wavelength of around 5 microns. https://photojournal.jpl.nasa.gov/catalog/PIA23560

This collage of images from NASA's Cassini spacecraft shows Saturn's northern hemisphere and rings as viewed with four different spectral filters. Each filter is sensitive to different wavelengths of light and reveals clouds and hazes at different altitudes. Clockwise from top left, the filters used are sensitive to violet (420 nanometers), red (648 nanometers), near-infrared (728 nanometers) and infrared (939 nanometers) light. The image was taken with the Cassini spacecraft wide-angle camera on Dec. 2, 2016, at a distance of about 400,000 miles (640,000 kilometers) from Saturn. Image scale is 95 miles (153 kilometers) per pixel. The images have been enlarged by a factor of two. The original versions of these images, as sent by the spacecraft, have a size of 256 pixels by 256 pixels. Cassini's images are sometimes planned to be compressed to smaller sizes due to data storage limitations on the spacecraft, or to allow a larger number of images to be taken than would otherwise be possible. These images were obtained about two days before its first close pass by the outer edges of Saturn's main rings during its penultimate mission phase. http://photojournal.jpl.nasa.gov/catalog/PIA21053

Robert Johnson, top, sets the lubricant flow while Donald Buckley adjusts the bearing specimen on an artificial hip simulator at the National Aeronautics and Space Administration (NASA) Lewis Research Center. The simulator was supplemented by large crystal lattice models to demonstrate the composition of different bearing alloys. This this image by NASA photographer Paul Riedel was used for the cover of the August 15, 1966 edition of McGraw-Hill Product Engineering. Johnson was chief of Lubrication Branch and Buckley head of the Space Environment Lubrication Section in the Fluid System Components Division. In 1962 they began studying the molecular structure of metals. Their friction and wear testing revealed that the optimal structure for metal bearings was a hexagonal crystal structure with proper molecular space. Bearing manufacturers traditionally preferred cubic structures over hexagonal arrangements. Buckley and Johnson found that even though the hexagonal structural was not as inherently strong as its cubic counterpart, it was less likely to cause a catastrophic failure. The Lewis researchers concentrated their efforts on cobalt-molybdenum and titanium alloys for high temperatures applications. The alloys had a number of possible uses, included prosthetics. The alloys were similar in composition to the commercial alloys used for prosthetics, but employed the longer lasting hexagonal structure.

NASA Cassini spacecraft captures three magnificent sights at once: Saturn north polar vortex and hexagon along with its expansive rings. The hexagon, which is wider than two Earths, owes its appearance to the jet stream that forms its perimeter. The jet stream forms a six-lobed, stationary wave which wraps around the north polar regions at a latitude of roughly 77 degrees North. This view looks toward the sunlit side of the rings from about 37 degrees above the ringplane. The image was taken with the Cassini spacecraft wide-angle camera on April 2, 2014 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 752 nanometers. The view was obtained at a distance of approximately 1.4 million miles (2.2 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 43 degrees. Image scale is 81 miles (131 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA18274

The Gemini 6 patch is hexagonal in shape, reflecting the mission number; and the spacecraft trajectory also traces out the number "6". The Gemini 6 spacecraft is shown superimposed on the "twin stars" Castor and Pollux, for "Gemini".

This view from NASA's Cassini spacecraft was obtained about half a day before its first close pass by the outer edges of Saturn's main rings during its penultimate mission phase. The view shows part of the giant, hexagon-shaped jet stream around the planet's north pole. Each side of the hexagon is about as wide as Earth. A circular storm lies at the center, at the pole (see PIA14944). The image was taken with the Cassini spacecraft wide-angle camera on Dec. 3, 2016, at a distance of about 240,000 miles (390,000 kilometers) from Saturn. Image scale is 14 miles (23 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA21052

This colorful view from NASA Cassini mission, known as the

These two natural color images from NASA's Cassini spacecraft show the changing appearance of Saturn's north polar region between 2012 and 2016. Scientists are investigating potential causes for the change in color of the region inside the north-polar hexagon on Saturn. The color change is thought to be an effect of Saturn's seasons. In particular, the change from a bluish color to a more golden hue may be due to the increased production of photochemical hazes in the atmosphere as the north pole approaches summer solstice in May 2017. Researchers think the hexagon, which is a six-sided jetstream, might act as a barrier that prevents haze particles produced outside it from entering. During the polar winter night between November 1995 and August 2009, Saturn's north polar atmosphere became clear of aerosols produced by photochemical reactions -- reactions involving sunlight and the atmosphere. Since the planet experienced equinox in August 2009, the polar atmosphere has been basking in continuous sunshine, and aerosols are being produced inside of the hexagon, around the north pole, making the polar atmosphere appear hazy today. Other effects, including changes in atmospheric circulation, could also be playing a role. Scientists think seasonally shifting patterns of solar heating probably influence the winds in the polar regions. Both images were taken by the Cassini wide-angle camera. http://photojournal.jpl.nasa.gov/catalog/PIA21049

ANDRÉ PASEUR (WELD TECHNICIAN, JACOBS ESTS GROUP/ERC) DISPLAYS A HEXAGON THAT WAS FABRICATED FROM FRICTION STIR WELDED PLATES OF 6AL-4V TITANIUM (ELI) USING THERMAL STIR WELDING. THIS WORK WAS PERFORMED FOR A NASA TECHNOLOGY TRANSFER INDUSTRIAL PARTNER (KEYSTONE SYNERGETIC ENTERPRISES, INC.) IN SUPPORT OF A PROJECT FOR THE U.S. NAVY

SAMUEL SMITH (WELD TECHNICIAN, JACOBS ESTS GROUP/ALL POINTS) DISPLAYS A HEXAGON THAT WAS FABRICATED FROM FRICTION STIR WELDED PLATES OF 6AL-4V TITANIUM (ELI) USING THERMAL STIR WELDING. THIS WORK WAS PERFORMED FOR A NASA TECHNOLOGY TRANSFER INDUSTRIAL PARTNER (KEYSTONE SYNERGETIC ENTERPRISES, INC.) IN SUPPORT OF A PROJECT FOR THE U.S. NAVY

The soil surface on Mars is believed to contain water ice, especially at higher latitudes. Similar to permafrost regions on Earth, this permanently frozen water remains geologically active. With the changing seasons, alternate cooling and warming causes the ice-cemented soil to contract and expand. Under favorable conditions these forces generate cracks into the hard frozen ground releasing the stresses caused by contraction. Over years of cyclic cracking, a curious honeycomb-like polygonal pattern arises. The presence of these widespread patterns on Mars present valuable clues as to the occurrence or absence of ice in the subsurface. This image shows a textbook example of regular, nearly hexagonal polygon networks. The geometry of the polygons reveals hints of how long the ice has been there and how deeply buried it may be. https://photojournal.jpl.nasa.gov/catalog/PIA24385

S65-55983 (8 Dec. 1965) --- This hexagonal-shaped insignia is the emblem of the Gemini-6 spaceflight. Astronauts Walter M. Schirra Jr., command pilot; and Thomas P. Stafford, pilot, are the prime crew. The National Aeronautics and Space Administration (NASA) has scheduled Gemini-6 as a two-day mission. Photo credit: NASA or National Aeronautics and Space Administration

SAMUEL SMITH (WELD TECHNICIAN, JACOBS ESTS GROUP/ALL POINTS) AND ANDRÉ PASEUR (WELD TECHNICIAN, JACOBS ESTS GROUP/ERC) DISPLAY TWO PROCESS DEMONSTRATION ARTICLES – A 9-FOOT BUTT WELD (FOREGROUND) AND A HEXAGON FABRICATED FROM FRICTION STIR WELDED PLATES (BACKGROUND) – THAT WERE FABRICATED FROM 6AL-4V TITANIUM (ELI) USING THERMAL STIR WELDING. THIS WORK WAS PERFORMED FOR A NASA TECHNOLOGY TRANSFER INDUSTRIAL PARTNER (KEYSTONE SYNERGETIC ENTERPRISES, INC.) IN SUPPORT OF A PROJECT FOR THE U.S. NAVY

Sunlight truly has come to Saturn's north pole. The whole northern region is bathed in sunlight in this view from late 2016, feeble though the light may be at Saturn's distant domain in the solar system. The hexagon-shaped jet-stream is fully illuminated here. In this image, the planet appears darker in regions where the cloud deck is lower, such the region interior to the hexagon. Mission experts on Saturn's atmosphere are taking advantage of the season and Cassini's favorable viewing geometry to study this and other weather patterns as Saturn's northern hemisphere approaches Summer solstice. This view looks toward the sunlit side of the rings from about 51 degrees above the ring plane. The image was taken with the Cassini spacecraft wide-angle camera on Sept. 9, 2016 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 728 nanometers. The view was obtained at a distance of approximately 750,000 miles (1.2 million kilometers) from Saturn. Image scale is 46 miles (74 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20513

NASA Administrator Bill Nelson, left, is shown an early mirror alignment image from the James Webb Space Telescope, by NASA Webb Optical Telescope Element Manager Lee Feinberg, Monday, Feb., 7, 2022, at the Mary W. Jackson NASA Headquarters building in Washington. This engineering visual, which features 18 unfocused dots of light, demonstrates that the Webb team has successfully identified starlight through each of Webb’s 18 hexagonal mirror segments – the starting point in a months-long process to progressively align the segments into a single, precise mirror to prepare the telescope for science. Photo Credit: (NASA/Bill Ingalls)

This wide-angle view depicts the Orbital Workshop (OWS) wardroom/galley located in the lower level of the OWS. The galley in the wardroom provided the daily supply of food; galley-located equipment was used for preparation and disposal of food. The Skylab astronauts used the wardroom as kitchen and dining room. The hexagonal food table, shown in the middle of this image, allowed three crewmen to simultaneously heat their food and eat their meals in an efficient and comfortable marner. Chairs were pointless in the zero-gravity environment. The table also supported components of the water system, including the water chiller and the wardroom water heater.

A team of engineers at Marshall Space Flight Center (MSFC) has designed, fabricated, and tested the first solar thermal engine, a non-chemical rocket that produces lower thrust but has better thrust efficiency than the chemical combustion engines. This segmented array of mirrors is the solar concentrator test stand at MSFC for firing the thermal propulsion engines. The 144 mirrors are combined to form an 18-foot diameter array concentrator. The mirror segments are aluminum hexagons that have the reflective surface cut into it by a diamond turning machine, which is developed by MSFC Space Optics Manufacturing Technology Center.

From high above Saturn's northern hemisphere, NASA's Cassini spacecraft gazes over the planet's north pole, with its intriguing hexagon and bullseye-like central vortex. Saturn's moon Mimas is visible as a mere speck near upper right. At 246 miles (396 kilometers across) across, Mimas is considered a medium-sized moon. It is large enough for its own gravity to have made it round, but isn't one of the really large moons in our solar system, like Titan. Even enormous Titan is tiny beside the mighty gas giant Saturn. This view looks toward Saturn from the sunlit side of the rings, from about 27 degrees above the ring plane. The image was taken in green light with the Cassini spacecraft wide-angle camera on March 27, 2017. The view was acquired at a distance of approximately 617,000 miles (993,000 kilometers) from Saturn. Image scale is 37 miles (59 kilometers) per pixel. Mimas' brightness has been enhanced by a factor of 3 in this image to make it easier to see. https://photojournal.jpl.nasa.gov/catalog/PIA21331

The globe of Saturn, seen here in natural color, is reminiscent of a holiday ornament in this wide-angle view from NASA's Cassini spacecraft. The characteristic hexagonal shape of Saturn's northern jet stream, somewhat yellow here, is visible. At the pole lies a Saturnian version of a high-speed hurricane, eye and all. This view is centered on terrain at 75 degrees north latitude, 120 degrees west longitude. Images taken using red, green and blue spectral filters were combined to create this natural-color view. The images were taken with the Cassini spacecraft wide-angle camera on July 22, 2013. This view was acquired at a distance of approximately 611,000 miles (984,000 kilometers) from Saturn. Image scale is 51 miles (82 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA17175

NASA Deputy Administrator Pam Melroy, left, NASA Associate Administrator Bob Cabana, and NASA Administrator Bill Nelson are shown an early mirror alignment image from the James Webb Space Telescope, by NASA Webb Optical Telescope Element Manager Lee Feinberg, as NASA Program Director for the James Webb Space Telescope Program Greg Robinson, right, looks on, Monday, Feb., 7, 2022, at the Mary W. Jackson NASA Headquarters building in Washington. This engineering visual, which features 18 unfocused dots of light, demonstrates that the Webb team has successfully identified starlight through each of Webb’s 18 hexagonal mirror segments – the starting point in a months-long process to progressively align the segments into a single, precise mirror to prepare the telescope for science. Photo Credit: (NASA/Bill Ingalls)

CAPE CANAVERAL, Fla. – At NASA's Kennedy Space Center in Florida, the 327-foot-tall Ares I-X rocket awaits liftoff on the hexagonally shaped Launch Pad 39B on its upcoming flight test. In the background is the Atlantic Ocean. This is the first time since the Apollo Program's Saturn rockets were retired that a vehicle other than the space shuttle has occupied the pad. Modifications to the pad to support the Ares I-X included the removal of shuttle unique subsystems, such as the orbiter access arm and a section of the gaseous oxygen vent arm, and the installation of three 600-foot lightning towers, access platforms, environmental control systems and a vehicle stabilization system. Part of the Constellation Program, the Ares I-X is the test vehicle for the Ares I. The Ares I-X flight test is set for Oct. 27. For information on the Ares I-X vehicle and flight test, visit http://www.nasa.gov/aresIX. Photo credit: NASA/Kim Shiflett

Saturn reigns supreme, encircled by its retinue of rings. Although all four giant planets have ring systems, Saturn's is by far the most massive and impressive. Scientists are trying to understand why by studying how the rings have formed and how they have evolved over time. Also seen in this image is Saturn's famous north polar vortex and hexagon. This view looks toward the sunlit side of the rings from about 37 degrees above the ringplane. The image was taken with the Cassini spacecraft wide-angle camera on May 4, 2014 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 752 nanometers. The view was acquired at a distance of approximately 2 million miles (3 million kilometers) from Saturn. Image scale is 110 miles (180 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA18278

Thirty kilometers southwest of Rome lies what may be ancient Rome's greatest engineering achievement: Portus. Built in the first century A.D., Portus was Rome's principal maritime harbor, replacing the port city of Ostia on the Tiber River (circled area) that had become inadequate to handle the hundreds of ships loaded with food stuffs to feed Rome's 1 million+ inhabitants. The hexagonal Trajanic Basin and the outer Claudian Basin (now silted up) formed a port complex without equal. In 2000 years, the coastline has moved seaward, and the Trajanic Basin is now a private lake. The image was acquired June 29, 2014, covers an area of 10 by 10 km, and is located at 41.7 degrees north, 12.3 degrees east. http://photojournal.jpl.nasa.gov/catalog/PIA19209

NASA's Dawn mission has found that craters on Ceres show a diversity of shapes that provide important clues about the structure of Ceres' subsurface. The bottom half of this pair of craters is called Fejokoo, named after the Nigerian god who supplied yams. The hexagonal shape of that 42-mile (68-kilometer) crater is probably due to the presence of fractures in the crust, along which the crater rims tend to align. Polygonal craters are frequent on Ceres. Most display six or seven sides, like in the case of Fejokoo, but a few nonagons -- nine-sided shapes -- have been discovered. Polygonal craters are also commonly found on other solar system bodies, such as Mars, Earth's moon and icy moons of giant planets. Dawn took this image on May 4, 2015, from an altitude of 915 miles (1,470 kilometers). The image has a resolution of 450 feet (140 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA21399

This image from InSight's robotic-arm mounted Instrument Deployment Camera shows the instruments on the spacecraft's deck, with the Martian surface of Elysium Planitia in the background. The color-calibrated picture was acquired on Dec. 4, 2018 (Sol 8). In the foreground, a copper-colored hexagonal cover protects the Seismic Experiment for Interior Structure instrument (SEIS), a seismometer that will measure marsquakes. The gray dome behind SEIS is the wind and thermal shield, which will be placed over SEIS. To the left is a black cylindrical instrument, the Heat Flow and Physical Properties Probe (HP3). HP3 will drill up to 16 feet (5 meters) below the Martian surface, measuring heat released from the interior of the planet. Above the deck is InSight's robotic arm, with the stowed grapple directly facing the camera. To the right can be seen a small portion of one of the two solar panels that help power InSight and part of the UHF communication antenna. https://photojournal.jpl.nasa.gov/catalog/PIA22871

A view of the one dozen (out of 18) flight mirror segments that make up the primary mirror on NASA's James Webb Space Telescope have been installed at NASA's Goddard Space Flight Center. Credits: NASA/Chris Gunn More: Since December 2015, the team of scientists and engineers have been working tirelessly to install all the primary mirror segments onto the telescope structure in the large clean room at NASA's Goddard Space Flight Center in Greenbelt, Maryland. The twelfth mirror was installed on January 2, 2016. "This milestone signifies that all of the hexagonal shaped mirrors on the fixed central section of the telescope structure are installed and only the 3 mirrors on each wing are left for installation," said Lee Feinberg, NASA's Optical Telescope Element Manager at NASA Goddard. "The incredibly skilled and dedicated team assembling the telescope continues to find ways to do things faster and more efficiently." Each hexagonal-shaped segment measures just over 4.2 feet (1.3 meters) across and weighs approximately 88 pounds (40 kilograms). After being pieced together, the 18 primary mirror segments will work together as one large 21.3-foot (6.5-meter) mirror. The primary mirror will unfold and adjust to shape after launch. The mirrors are made of ultra-lightweight beryllium. The mirrors are placed on the telescope's backplane using a robotic arm, guided by engineers. The full installation is expected to be completed in a few months. The mirrors were built by Ball Aerospace & Technologies Corp., Boulder, Colorado. Ball is the principal subcontractor to Northrop Grumman for the optical technology and lightweight mirror system. The installation of the mirrors onto the telescope structure is performed by Harris Corporation of Rochester, New York. Harris Corporation leads integration and testing for the telescope. While the mirror assembly is a very significant milestone, there are many more steps involved in assembling the Webb telescope. The primary mirror and the tennis-court-sized sunshield are the largest and most visible components of the Webb telescope. However, there are four smaller components that are less visible, yet critical. The instruments that will fly aboard Webb - cameras and spectrographs with detectors able to record extremely faint signals — are part of the Integrated Science Instrument Module (ISIM), which is currently undergoing its final cryogenic vacuum test and will be integrated with the mirror later this year.

Caption: One dozen (out of 18) flight mirror segments that make up the primary mirror on NASA's James Webb Space Telescope have been installed at NASA's Goddard Space Flight Center. Credits: NASA/Chris Gunn More: Since December 2015, the team of scientists and engineers have been working tirelessly to install all the primary mirror segments onto the telescope structure in the large clean room at NASA's Goddard Space Flight Center in Greenbelt, Maryland. The twelfth mirror was installed on January 2, 2016. "This milestone signifies that all of the hexagonal shaped mirrors on the fixed central section of the telescope structure are installed and only the 3 mirrors on each wing are left for installation," said Lee Feinberg, NASA's Optical Telescope Element Manager at NASA Goddard. "The incredibly skilled and dedicated team assembling the telescope continues to find ways to do things faster and more efficiently." Each hexagonal-shaped segment measures just over 4.2 feet (1.3 meters) across and weighs approximately 88 pounds (40 kilograms). After being pieced together, the 18 primary mirror segments will work together as one large 21.3-foot (6.5-meter) mirror. The primary mirror will unfold and adjust to shape after launch. The mirrors are made of ultra-lightweight beryllium. The mirrors are placed on the telescope's backplane using a robotic arm, guided by engineers. The full installation is expected to be completed in a few months. The mirrors were built by Ball Aerospace & Technologies Corp., Boulder, Colorado. Ball is the principal subcontractor to Northrop Grumman for the optical technology and lightweight mirror system. The installation of the mirrors onto the telescope structure is performed by Harris Corporation of Rochester, New York. Harris Corporation leads integration and testing for the telescope. While the mirror assembly is a very significant milestone, there are many more steps involved in assembling the Webb telescope. The primary mirror and the tennis-court-sized sunshield are the largest and most visible components of the Webb telescope. However, there are four smaller components that are less visible, yet critical. The instruments that will fly aboard Webb - cameras and spectrographs with detectors able to record extremely faint signals — are part of the Integrated Science Instrument Module (ISIM), which is currently undergoing its final cryogenic vacuum test and will be integrated with the mirror later this year.

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unfurl a solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

STS058-S-001 (May 1993) --- Designed by members of the flight crew, the STS-58 insignia depicts the space shuttle Columbia with a Spacelab module in its payload bay in orbit around Earth. The Spacelab and the lettering "Spacelab Life Sciences II" highlight the primary mission of the second space shuttle flight dedicated to life sciences research. An Extended Duration Orbiter (EDO) support pallet is shown in the aft payload bay, stressing the scheduled two-week duration of the longest space shuttle mission to date. The hexagonal shape of the patch depicts the carbon ring, a molecule common to all living organisms. Encircling the inner border of the patch is the double helix of DNA, representing the genetic basis of life. Its yellow background represents the sun, energy source for all life on Earth. Both medical and veterinary caducei are shown to represent the STS-58 life sciences experiments. The position of the spacecraft in orbit about Earth with the United States in the background symbolizes the ongoing support of the American people for scientific research intended to benefit all mankind. The NASA insignia design for space shuttle flights is reserved for use by the astronauts and for other official use as the NASA Administrator may authorize. Public availability has been approved only in the form of illustrations by the various news media. When and if there is any change in this policy, which we do not anticipate, it will be publicly announced. Photo credit: NASA

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., test the electrical continuity of a solar array that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., test the electrical continuity of a solar array that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., prepare to unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

The night sides of Saturn and Tethys are dark places indeed. We know that shadows are darker areas than sunlit areas, and in space, with no air to scatter the light, shadows can appear almost totally black. Tethys (660 miles or 1,062 kilometers across) is just barely seen in the lower left quadrant of this image below the ring plane and has been brightened by a factor of three to increase its visibility. The wavy outline of Saturn's polar hexagon is visible at top center. This view looks toward the sunlit side of the rings from about 10 degrees above the ring plane. The image was taken with the Cassini spacecraft wide-angle camera on Jan. 15, 2015 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 752 nanometers. The view was obtained at a distance of approximately 1.5 million miles (2.4 million kilometers) from Saturn. Image scale is 88 miles (141 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA18333

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- A solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter is unpacked in the Astrotech payload processing facility in Titusville, Fla. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

TITUSVILLE, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unpack a solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., prepare to unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., prepare to unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., test the electrical continuity of a solar array that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., check out solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

As Saturn's northern hemisphere summer approaches, the shadows of the rings creep ever southward across the planet. Here, the ring shadows appear to obscure almost the entire southern hemisphere, while the planet's north pole and its six-sided jet stream, known as "the hexagon," are fully illuminated by the sun. When NASA's Cassini spacecraft arrived at Saturn 12 years ago, the shadows of the rings lay far to the north on the planet (see PIA06077). As the mission progressed and seasons turned on the slow-orbiting giant, equinox arrived and the shadows of the rings became a thin line at the equator (see PIA11667). This view looks toward the sunlit side of the rings from about 16 degrees above the ring plane. The image was taken in red light with the Cassini spacecraft wide-angle camera on March 19, 2016. The view was obtained at a distance of approximately 1.7 million miles (2.7 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 92 degrees. Image scale is 100 miles (160 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20486

NASA's Cassini spacecraft stared at Saturn for nearly 44 hours on April 25 to 27, 2016, to obtain this movie showing just over four Saturn days. With Cassini's orbit being moved closer to the planet in preparation for the mission's 2017 finale, scientists took this final opportunity to capture a long movie in which the planet's full disk fit into a single wide-angle camera frame. Visible at top is the giant hexagon-shaped jet stream that surrounds the planet's north pole. Each side of this huge shape is slightly wider than Earth. The resolution of the 250 natural color wide-angle camera frames comprising this movie is 512x512 pixels, rather than the camera's full resolution of 1024x1024 pixels. Cassini's imaging cameras have the ability to take reduced-size images like these in order to decrease the amount of data storage space required for an observation. The spacecraft began acquiring this sequence of images just after it obtained the images to make a three-panel color mosaic. When it began taking images for this movie sequence, Cassini was 1,847,000 miles (2,973,000 kilometers) from Saturn, with an image scale of 355 kilometers per pixel. When it finished gathering the images, the spacecraft had moved 171,000 miles (275,000 kilometers) closer to the planet, with an image scale of 200 miles (322 kilometers) per pixel. A movie is available at http://photojournal.jpl.nasa.gov/catalog/PIA21047

The 18th and final primary mirror segment is installed on what will be the biggest and most powerful space telescope ever launched. The final mirror installation Wednesday at NASA’s Goddard Space Flight Center in Greenbelt, Maryland marks an important milestone in the assembly of the agency’s James Webb Space Telescope. “Scientists and engineers have been working tirelessly to install these incredible, nearly perfect mirrors that will focus light from previously hidden realms of planetary atmospheres, star forming regions and the very beginnings of the Universe,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “With the mirrors finally complete, we are one step closer to the audacious observations that will unravel the mysteries of the Universe.” Using a robotic arm reminiscent of a claw machine, the team meticulously installed all of Webb's primary mirror segments onto the telescope structure. Each of the hexagonal-shaped mirror segments measures just over 4.2 feet (1.3 meters) across -- about the size of a coffee table -- and weighs approximately 88 pounds (40 kilograms). Once in space and fully deployed, the 18 primary mirror segments will work together as one large 21.3-foot diameter (6.5-meter) mirror. Credit: NASA/Goddard/Chris Gunn Credits: NASA/Chris Gunn

S71-39481 (July 1971) --- An artist's concept showing TRW's small lunar subsatellite being ejected into lunar orbit from the SIM bay of the Apollo 15 Service Module. The 80-pound satellite will remain in orbit a year or more, carrying scientific experiments to study space in the vicinity of the moon. The satellite carries three experiments: S-Band Transponder; Particle Shadows/Boundary Layer Experiment; and Subsatellite Magnetometer Experiment. The subsatellite is housed in a container resembling a rural mailbox, and when deployed is spring-ejected out-of-plane at 4 fps with a spin rate of 140 rpm. After the satellite booms are deployed, the spin rate is stabilized at about 12 rpm. The subsatellite is 31 inches long and has a 14 inch hexagonal diameter. The exact weight is 78.5 pounds. The folded booms deploy to a length of five feet. Subsatellite electrical power is supplied by a solar cell array outputting 25 watts for dayside operation and a rechargeable silver-cadmium battery for nightside passes.

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., test the electrical continuity of a solar array, left, that will help power NASA's Juno spacecraft on a mission to Jupiter. Two other arrays are in work stands on the right. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

TITUSVILLE, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., process a solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., prepare to unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

S82-39531 (December 1982) --- This is the official insignia for space shuttle mission STS-6. The crew members for this mission are astronauts Paul J. Weitz, commander; Karol J. Bobko, pilot; F. Story Musgrave, mission specialist; and Donald H. Peterson, mission specialist. The sixth space shuttle flight is represented by the hexagonal shape of the insignia and the six stars, in the portrayed constellation Virgo. The sign Virgo is also symbolic of the first flight of the space shuttle Challenger. Depicted above the spacecraft?s open cargo bay is the combined Inertial Upper Stage (IUS) and a Tracking and Data Relay Satellite. This is the first shuttle flight of the IUS rocket, which will carry the first TDRS to a geosynchronous orbit of 24,000 statute miles. The NASA insignia design for space shuttle flights is reserved for use by the astronauts and for other official use as the NASA Administrator may authorize. Public availability has been approved only in the forms of illustrations by the various news media. When and if there is any change in this policy, which is not anticipated, the change will be publicly announced. Photo credit: NASA

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unfurl a solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

TITUSVILLE, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., process a solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., begin to unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- The electrical continuity of a solar array that will help power NASA's Juno spacecraft on a mission to Jupiter is tested in the Astrotech payload processing facility in Titusville, Fla. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., prepare to test the electrical continuity of a solar array that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

ISS004-S-001 (August 2001) --- The International Space Station (ISS) Expedition 4 crew patch has an overall diamond shape, showing the “diamond in the rough” configuration of the Station during expedition 4. The red hexagonal shape with stylized American and Russian flags represents the cross-sectional view of the S0 truss segment, which the crew will attach to the U.S. Lab Destiny. The persistent Sun shining on the Earth and Station represents the constant challenges that the crew and ground support team will face every day while operating the International Space Station, while shedding new light through daily research. The green portion of the Earth represents the fourth color in the visible spectrum and the black void of space represents humankind’s constant quest to explore the unknown. The NASA insignia design for Shuttle flights is reserved for use by the astronauts and for other official use as the NASA Administrator may authorize. Public availability has been approved only in the forms of illustrations by the various news media. When and if there is any change in this policy, which is not anticipated, the change will be publicly announced.

Designed by members of the flight crew, the STS-58 insignia depicts the Space Shuttle Columbia with a Spacelab module in its payload bay in orbit around Earth. The Spacelab and the lettering Spacelab Life Sciences ll highlight the primary mission of the second Space Shuttle flight dedicated to life sciences research. An Extended Duration Orbiter (EDO) support pallet is shown in the aft payload bay, stressing the scheduled two-week duration of the longest Space Shuttle mission to date. The hexagonal shape of the patch depicts the carbon ring, a molecule common to all living organisms. Encircling the inner border of the patch is the double helix of DNA, representing the genetic basis of life. Its yellow background represents the sun, energy source for all life on Earth. Both medical and veterinary caducei are shown to represent the STS- 58 life sciences experiments. The position of the spacecraft in orbit about Earth with the United States in the background symbolizes the ongoing support of the American people for scientific research intended to benefit all mankind.

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., begin to unfurl a solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- The electrical continuity of a solar array that will help power NASA's Juno spacecraft on a mission to Jupiter is tested in the Astrotech payload processing facility in Titusville, Fla. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

JOHNSON SPACE CENTER, HOUSTON, TEXAS -- EXPEDITION FOUR INSIGNIA -- The International Space Station (ISS) Expedition Four crew patch has an overall diamond shape, showing the "diamond in the rough" configuration of the Station during expedition four. The red hexagonal shape with stylized American and Russian flags represents the cross-sectional view of the S0 truss segment, which the crew will attach to the U.S. Lab Destiny. The persistent Sun shining on the Earth and Station represents the constant challenges that the crew and ground support team will face every day while operating the International Space Station, while shedding new light through daily research. The green portion of the Earth represents the fourth color in the visible spectrum and the black void of space represents humankind's constant quest to explore the unknown. The NASA insignia design for Shuttle flights ts is reserved for use by the astronauts and for other official use as the NASA Administrator may authorize. Public availability has been approved only in the forms of illustrations by the various news media. When and if there is any change in this policy, which we do not anticipate, it will be publicly announced

TITUSVILLE, Fla. -- A solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter is unpacked in the Astrotech payload processing facility in Titusville, Fla. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

Saturn's north polar region displays its beautiful bands and swirls, which somewhat resemble the brushwork in a watercolor painting. Each latitudinal band represents air flowing at different speeds, and clouds at different heights, compared to neighboring bands. Where they meet and flow past each other, the bands' interactions produce many eddies and swirls. The northern polar region of Saturn is dominated by the famous hexagon shape (see PIA11682) which itself circumscribes the northern polar vortex -- seen as a dark spot at the planet's pole in the above image-- which is understood to the be eye of a hurricane-like storm (PIA14946). This view looks toward the sunlit side of the rings from about 20 degrees above the ring plane. The image was taken with the Cassini spacecraft wide-angle camera on Sept. 5, 2016 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 728 nanometers. The view was obtained at a distance of approximately 890,000 miles (1.4 million kilometers) from Saturn. Image scale is 53 miles (86 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20507

ISS043-S-001 (April 2013) --- The hexagon (six-sided) shape of the Expedition 43 patch represents the six crew members living and working onboard the orbital outpost. The International Space Station (ISS) is portrayed in orbit around the Earth, representing the multi-national partnership that has constructed, developed, and continues to operate the ISS for the benefit of all humankind. The sunrise marks the beginning of a new day, reflecting the fact that we're at the dawn of our history as a space faring species. The moon and planets represent future exploration of our solar system, for which the ISS is a stepping stone. Finally, the five stars honor the crews who have lost their lives during the pursuit of human spaceflight. The NASA insignia design for shuttle flights and station increments is reserved for use by the astronauts and for other official use as the NASA Administrator may authorize. Public availability has been approved only in the forms of illustrations by the various news media. When and if there is any change in this policy, which is not anticipated, the change will be publicly announced. Photo credit: NASA

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., test the electrical continuity of a solar array that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

TITUSVILLE, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unpack a solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., check out an unfurled solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., begin processing a solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., test the electrical continuity of a solar array that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unpack a solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

A view of the one dozen (out of 18) flight mirror segments that make up the primary mirror on NASA's James Webb Space Telescope have been installed at NASA's Goddard Space Flight Center. Credits: NASA/Chris Gunn More: Since December 2015, the team of scientists and engineers have been working tirelessly to install all the primary mirror segments onto the telescope structure in the large clean room at NASA's Goddard Space Flight Center in Greenbelt, Maryland. The twelfth mirror was installed on January 2, 2016. &quot;This milestone signifies that all of the hexagonal shaped mirrors on the fixed central section of the telescope structure are installed and only the 3 mirrors on each wing are left for installation,&quot; said Lee Feinberg, NASA's Optical Telescope Element Manager at NASA Goddard. &quot;The incredibly skilled and dedicated team assembling the telescope continues to find ways to do things faster and more efficiently.&quot; Each hexagonal-shaped segment measures just over 4.2 feet (1.3 meters) across and weighs approximately 88 pounds (40 kilograms). After being pieced together, the 18 primary mirror segments will work together as one large 21.3-foot (6.5-meter) mirror. The primary mirror will unfold and adjust to shape after launch. The mirrors are made of ultra-lightweight beryllium. The mirrors are placed on the telescope's backplane using a robotic arm, guided by engineers. The full installation is expected to be completed in a few months. The mirrors were built by Ball Aerospace &amp; Technologies Corp., Boulder, Colorado. Ball is the principal subcontractor to Northrop Grumman for the optical technology and lightweight mirror system. The installation of the mirrors onto the telescope structure is performed by Harris Corporation of Rochester, New York. Harris Corporation leads integration and testing for the telescope. While the mirror assembly is a very significant milestone, there are many more steps involved in assembling the Webb telescope. The primary mirror and the tennis-court-sized sunshield are the largest and most visible components of the Webb telescope. However, there are four smaller components that are less visible, yet critical. The instruments that will fly aboard Webb - cameras and spectrographs with detectors able to record extremely faint signals — are part of the Integrated Science Instrument Module (ISIM), which is currently undergoing its final cryogenic vacuum test and will be integrated with the mirror later this year. Read more: <a href="http://www.nasa.gov/feature/goddard/2016/by-the-dozen-nasas-james-webb-space-telescope-mirrors" rel="nofollow">www.nasa.gov/feature/goddard/2016/by-the-dozen-nasas-jame...</a> <b><a href="http://www.nasa.gov/audience/formedia/features/MP_Photo_Guidelines.html" rel="nofollow">NASA image use policy.</a></b> <b><a href="http://www.nasa.gov/centers/goddard/home/index.html" rel="nofollow">NASA Goddard Space Flight Center</a></b> enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. <b>Follow us on <a href="http://twitter.com/NASAGoddardPix" rel="nofollow">Twitter</a></b> <b>Like us on <a href="http://www.facebook.com/pages/Greenbelt-MD/NASA-Goddard/395013845897?ref=tsd" rel="nofollow">Facebook</a></b> <b>Find us on <a href="http://instagrid.me/nasagoddard/?vm=grid" rel="nofollow">Instagram</a></b>

Caption: One dozen (out of 18) flight mirror segments that make up the primary mirror on NASA's James Webb Space Telescope have been installed at NASA's Goddard Space Flight Center. Credits: NASA/Chris Gunn More: Since December 2015, the team of scientists and engineers have been working tirelessly to install all the primary mirror segments onto the telescope structure in the large clean room at NASA's Goddard Space Flight Center in Greenbelt, Maryland. The twelfth mirror was installed on January 2, 2016. &quot;This milestone signifies that all of the hexagonal shaped mirrors on the fixed central section of the telescope structure are installed and only the 3 mirrors on each wing are left for installation,&quot; said Lee Feinberg, NASA's Optical Telescope Element Manager at NASA Goddard. &quot;The incredibly skilled and dedicated team assembling the telescope continues to find ways to do things faster and more efficiently.&quot; Each hexagonal-shaped segment measures just over 4.2 feet (1.3 meters) across and weighs approximately 88 pounds (40 kilograms). After being pieced together, the 18 primary mirror segments will work together as one large 21.3-foot (6.5-meter) mirror. The primary mirror will unfold and adjust to shape after launch. The mirrors are made of ultra-lightweight beryllium. The mirrors are placed on the telescope's backplane using a robotic arm, guided by engineers. The full installation is expected to be completed in a few months. The mirrors were built by Ball Aerospace &amp; Technologies Corp., Boulder, Colorado. Ball is the principal subcontractor to Northrop Grumman for the optical technology and lightweight mirror system. The installation of the mirrors onto the telescope structure is performed by Harris Corporation of Rochester, New York. Harris Corporation leads integration and testing for the telescope. While the mirror assembly is a very significant milestone, there are many more steps involved in assembling the Webb telescope. The primary mirror and the tennis-court-sized sunshield are the largest and most visible components of the Webb telescope. However, there are four smaller components that are less visible, yet critical. The instruments that will fly aboard Webb - cameras and spectrographs with detectors able to record extremely faint signals — are part of the Integrated Science Instrument Module (ISIM), which is currently undergoing its final cryogenic vacuum test and will be integrated with the mirror later this year. Read more: <a href="http://www.nasa.gov/feature/goddard/2016/by-the-dozen-nasas-james-webb-space-telescope-mirrors" rel="nofollow">www.nasa.gov/feature/goddard/2016/by-the-dozen-nasas-jame...</a> <b><a href="http://www.nasa.gov/audience/formedia/features/MP_Photo_Guidelines.html" rel="nofollow">NASA image use policy.</a></b> <b><a href="http://www.nasa.gov/centers/goddard/home/index.html" rel="nofollow">NASA Goddard Space Flight Center</a></b> enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. <b>Follow us on <a href="http://twitter.com/NASAGoddardPix" rel="nofollow">Twitter</a></b> <b>Like us on <a href="http://www.facebook.com/pages/Greenbelt-MD/NASA-Goddard/395013845897?ref=tsd" rel="nofollow">Facebook</a></b> <b>Find us on <a href="http://instagrid.me/nasagoddard/?vm=grid" rel="nofollow">Instagram</a></b>

This mosaic of images combines views captured by NASA's Cassini spacecraft as it made the first dive of the mission's Grand Finale on April 26, 2017. It shows a vast swath of Saturn's atmosphere, from the north polar vortex to the boundary of the hexagon-shaped jet stream, to details in bands and swirls at middle latitudes and beyond. The mosaic is a composite of 137 images captured as Cassini made its first dive toward the gap between Saturn and its rings. It is an update to a previously released image product. In the earlier version, the images were presented as individual movie frames, whereas here, they have been combined into a single, continuous mosaic. The mosaic is presented as a still image as well as a video that pans across its length. Imaging scientists referred to this long, narrow mosaic as a "noodle" in planning the image sequence. The first frame of the mosaic is centered on Saturn's north pole, and the last frame is centered on a region at 18 degrees north latitude. During the dive, the spacecraft's altitude above the clouds changed from 45,000 to 3,200 miles (72,400 to 8374 kilometers), while the image scale changed from 5.4 miles (8.7 kilometers) per pixel to 0.6 mile (1 kilometer) per pixel. The bottom of the mosaic (near the end of the movie) has a curved shape. This is where the spacecraft rotated to point its high-gain antenna in the direction of motion as a protective measure before crossing Saturn's ring plane. The images in this sequence were captured in visible light using the Cassini spacecraft wide-angle camera. The original versions of these images, as sent by the spacecraft, have a size of 512 by 512 pixels. The small image size was chosen in order to allow the camera to take images quickly as Cassini sped over Saturn. These images of the planet's curved surface were projected onto a flat plane before being combined into a mosaic. Each image was mapped in stereographic projection centered at 55 degree north latitude. A movie is available at https://photojournal.jpl.nasa.gov/catalog/PIA21617

2010/107 - 04/17 at 21 :05 UTC. Open-cell and closed-cell clouds off Peru, Pacific Ocean Resembling a frosted window on a cold winter's day, this lacy pattern of marine clouds was captured off the coast of Peru in the Pacific Ocean by the MODIS on the Aqua satellite on April 19, 2010. The image reveals both open- and closed-cell cumulus cloud patterns. These cells, or parcels of air, often occur in roughly hexagonal arrays in a layer of fluid (the atmosphere often behaves like a fluid) that begins to &quot;boil,&quot; or convect, due to heating at the base or cooling at the top of the layer. In &quot;closed&quot; cells warm air is rising in the center, and sinking around the edges, so clouds appear in cell centers, but evaporate around cell edges. This produces cloud formations like those that dominate the lower left. The reverse flow can also occur: air can sink in the center of the cell and rise at the edge. This process is called &quot;open cell&quot; convection, and clouds form at cell edges around open centers, which creates a lacy, hollow-looking pattern like the clouds in the upper right. Closed and open cell convection represent two stable atmospheric configurations — two sides of the convection coin. But what determines which path the &quot;boiling&quot; atmosphere will take? Apparently the process is highly chaotic, and there appears to be no way to predict whether convection will result in open or closed cells. Indeed, the atmosphere may sometimes flip between one mode and another in no predictable pattern. Satellite: Aqua NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team To learn more about MODIS go to: <a href="http://rapidfire.sci.gsfc.nasa.gov/gallery/?latest" rel="nofollow">rapidfire.sci.gsfc.nasa.gov/gallery/?latest</a> <b><a href="http://www.nasa.gov/centers/goddard/home/index.html" rel="nofollow">NASA Goddard Space Flight Center</a></b> is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

ISS017-E-008188 (29 May 2008) --- Dry Tortugas islands near Florida are featured in this image photographed by an Expedition 17 crewmember on the International Space Station. The Dry Tortugas are a group of islands located approximately 75 miles west of Key West, Florida; they form the western end of the Florida Keys in the Gulf of Mexico. Like the Keys, the Dry Tortugas are formed primarily of coral reefs over older limestone formations. The islands were named "Dry Tortugas" upon discovery by Ponce de Leon in 1513 -- "tortugas" means turtles in Spanish, and the islands are "dry" as no fresh water is found on them. From the air, the islands present an atoll-like arrangement, however no central volcanic structure is present. The islands are only accessible by boat or seaplane; nevertheless they have been designated the Dry Tortugas National Park, and are visited by hundreds every year. This view highlights three islands in the group; Bush Key, Hospital Key, and Garden Key -- the site of Fort Jefferson. Fort Jefferson is a Civil War era fort, perhaps most notable for being the prison of Dr. Samuel Mudd, who set the broken leg of John Wilkes Booth following Booth's assassination of President Lincoln. The fort itself is currently undergoing extensive restoration to prevent collapse of the hexagonal outer walls (center). The islands stand out due to brown and light tan carbonate sands visible above the Gulf of Mexico water surface. Light blue-green irregular masses in the image surrounding the islands are coral reef tops visible below the water surface.

NASA's Curiosity Mars rover found preserved, ancient mud cracks that scientists believe were formed after long cycles of wet and dry conditions over many years. The discovery marks the first evidence of these wet-dry cycles on Mars. The cracks were found while the rover explored a transitional region between an area enriched with clay minerals and one enriched with sulfate minerals. The mud cracks were captured in this mosaic by Curiosity's Mastcam on June 20, 2021, the 3,154th Martian day, or sol, of the mission. The mosaic is made up of 143 images that were stitched together after being sent back to Earth. The hexagonal shapes are similar to those found at locations on Earth such as Death Valley National Park's Racetrack playa. They form only after many years of alternating wet and dry conditions. When the mud cracks initially form, they have sharp, T-shaped angles within their "pits." After being gently rehydrated many times, those sharp angles soften into Y-shapes that become ridges as the rock is eroded. Evidence pointing to wet-dry cycles is exciting to Curiosity's scientists because while no one is exactly sure how life first forms, one prevailing theory suggests that these wet-dry cycles are supportive, perhaps even required. The conditions that sustain microbial life – a long-lasting lake, for example – differ from those that scientists think kickstart the chemical reactions that might lead to life. Driving those chemical reactions are long chains of carbon-based molecules called polymers, which require just the right conditions. Water is needed to mix chemicals into a soup, where they can react with one another. Too much water will dilute the soup, making it difficult for polymer-forming chemical reactions to occur; too little water, and the chemicals can't adequately mix and react. Wet-dry cycling can strike a balance between the two. https://photojournal.jpl.nasa.gov/catalog/PIA25915

Since NASA's Cassini spacecraft arrived at Saturn in mid-2004, the planet's appearance has changed greatly. The shifting angle of sunlight as the seasons march forward has illuminated the giant hexagon-shaped jet stream around the north polar region, and the subtle bluish hues seen earlier in the mission have continued to fade. Earlier views obtained in 2004 and 2009 (see PIA06077 and PIA11667) demonstrate how drastically the illumination has changed. This view shows Saturn's northern hemisphere in 2016, as that part of the planet nears its northern hemisphere summer solstice in May 2017. Saturn's year is nearly 30 Earth years long, and during its long time there, Cassini has observed winter and spring in the north, and summer and fall in the south. The spacecraft will complete its mission just after northern summer solstice, having observed long-term changes in the planet's winds, temperatures, clouds and chemistry. Cassini scanned across the planet and its rings on April 25, 2016, capturing three sets of red, green and blue images to cover this entire scene showing the planet and the main rings. The images were obtained using Cassini's wide-angle camera at a distance of approximately 1.9 million miles (3 million kilometers) from Saturn and at an elevation of about 30 degrees above the ring plane. The view looks toward the sunlit side of the rings from a sun-Saturn-spacecraft angle, or phase angle, of 55 degrees. Image scale on Saturn is about 111 miles (178 kilometers) per pixel. The exposures used to make this mosaic were obtained just prior to the beginning of a 44-hour movie sequence. http://photojournal.jpl.nasa.gov/catalog/PIA21046