Artist impression of the Rosetta orbiter at comet 67P/Churyumova-Gerasimenko. The image is not to scale.
Rosetta at Comet
Scientists from the European Space Agency Rosetta team have honored two late team members by naming comet features after them. The comet is 67P/Churyumov-Gerasimenko, where the mission successfully landed a probe.  One of the features is shown here in these Rosetta images, with the picture on the right being a close-up view. The "C. Alexander Gate" is found on the comet's smaller lobe, and is dedicated to Claudia Alexander, the U.S. project scientist from NASA's Jet Propulsion Laboratory, Pasadena, California, who passed away in July of this year.  Image credit left: ESA's comet viewer http://sci.esa.int/comet-viewer.  http://photojournal.jpl.nasa.gov/catalog/PIA19838
Comet Scientists Honor Colleagues
The European Space Agency's Rosetta mission concluded its study of comet 67P/Churyumov-Gerasimenko on Sept. 30, 2016. NASA's planet-hunting Kepler spacecraft observed the comet during the final month of the Rosetta mission, while the comet was not visible from Earth. This animation is composed of images from Kepler of the comet.  From Sept. 7 through Sept. 20, the Kepler spacecraft, operating in its K2 mission, fixed its gaze on comet 67P. From the distant vantage point of Kepler, the comet's nucleus and tail could be observed. The long-range view from Kepler complements the closeup view of the Rosetta spacecraft, providing context for the high-resolution investigation Rosetta performed as it descended closer and closer to the comet.  During the two-week period of study, Kepler took a picture of the comet every 30 minutes. The animation shows a period of 29.5 hours of observation from Sept. 17 thru Sept. 18. The comet is seen passing through Kepler's field of view from top right to bottom left, as outlined by the diagonal strip. The white dots represent stars and other regions in space studied during K2's tenth observing campaign.  As a comet travels through space it sheds a tail of gas and dust. The more material that is shed, the more surface area there is to reflect sunlight. A comet's activity level can be obtained by measuring the reflected sunlight. Analyzing the Kepler data, scientists will be able to determine the amount of mass lost each day as comet 67P travels through the solar system.  An animation is available at http://photojournal.jpl.nasa.gov/catalog/PIA21072
Comet 67P Seen by Kepler
Comet C/2019 Q4 as imaged by the Canada-France-Hawaii Telescope on Hawaii's Big Island on Sept. 10, 2019.  https://photojournal.jpl.nasa.gov/catalog/PIA23462
Comet C/2019 Q4
A composite image from a camera on ESA Rosetta mission Philae comet lander shows a solar array, with comet 67P/Churyumov-Gerasimenko in the background.
Rosetta Selflessly Offers Beautiful Comet Selfie
Image of the southern polar regions of comet 67P/Churyumov-Gerasimenko taken by Rosetta Optical, Spectroscopic, and Infrared Remote Imaging System OSIRIS on September 29, 2014, when the comet was still experiencing the long southern winter.  http://photojournal.jpl.nasa.gov/catalog/PIA19969
Taking a Comet Temperature
A 3D image shows what it would look like to fly over the surface of comet 67P/Churyumov-Gerasimenko. The image was generated by data collected by ESA Philae spacecraft during the decent to the spacecraft initial touchdown on the comet Nov. 12, 2014.
Rosetta Comet in 3-D
This still from a sequence of images shows comet 67P/Churyumov-Gerasimenko moving against the background star field.
Rosetta Comet Comes Alive
This image from ESA Rosetta spacecraft is of 67P/Churyumov-Gerasimenko shows the diversity of surface structures on the comet nucleus.
Comet Surface Variations
Comet NEOWISE is seen before sunrise over Washington, Sunday, July 12, 2020. The comet was discovered by NASA’s Near-Earth Object Wide-field Infrared Survey Explorer, or NEOWISE, on March 27. Since then, the comet — called comet C/2020 F3 NEOWISE and nicknamed comet NEOWISE — has been spotted by several NASA spacecraft, including Parker Solar Probe, NASA’s Solar and Terrestrial Relations Observatory, the ESA/NASA Solar and Heliospheric Observatory, and astronauts aboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)
Comet NEOWISE Over Washington
As comets C/2012 S1 ISON and the well-known short-period comet 2P/Encke both approached their closest distances to the Sun in November, 2013, they also passed close to the MESSENGER spacecraft orbiting the innermost planet Mercury.
MESSENGER First Images of Comets Encke and ISON
This image of comet 67P/Churyumov-Gerasimenko was obtained on October 30, 2014 by the OSIRIS scientific imaging system on the Rosetta spacecraft. The saturation of the image allows the viewer to see some surface structures on dark side of the comet.
Dark Side of Comet 67P/Churyumov-Gerasimenko Saturated
This frame from an animated sequence combined 36 interpolated images of comet 67P/Churyumov-Gerasimenko, each separated by 20 minutes. This comet is the destination for the European Space Agency Rosetta mission in 2014.
Rotation and Shape of Rosetta Mission Target Comet
This image of comet 67P/Churyumov-Gerasimenko was taken by the Philae lander of the European Space Agency Rosetta mission during Philae descent toward the comet on Nov. 12, 2014 from a distance of approximate two miles three kilometers.
View of Comet from Lander During Descent
NASA NEOWISE mission captured this series of pictures of comet C/2012 K1 -- also known as comet Pan-STARRS -- as it swept across our skies on May 20, 2014.
Infrared View of a Comet and Distant Galaxy
Comet C/2014 Q2 Lovejoy is one of more than 32 comets imaged by NASA NEOWISE mission from December 2013 to December 2014. This image of comet Lovejoy combines a series of observations made in November 2013.
NASA NEOWISE Images Comet C/2014 Q2 Lovejoy
This composite is a mosaic comprising four individual Rosetta NAVCAM images taken from 19 miles 31 kilometers from the center of comet 67P/Churyumov-Gerasimenko on Nov. 20, 2014.
Rosetta Comet
Comet C/2020 F3 NEOWISE appears as a string of fuzzy red dots in this composite of several heat-sensitive infrared images taken by NASA's Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) mission on March 27, 2020. The comet was discovered using these images to track its motion across the sky against the backdrop of stationary stars and galaxies. These images have been processed such that cyan colors represent NEOWISE's 3.4-micron channel (a wavelength of light approximately seven times longer than the green light that humans see), and red colors represent the NEOWISE 4.6-micron channel. The comet's extended halo, or coma, of gas and dust was already apparent in the discovery images. The comet appears much redder than the background stars and galaxies because it is much cooler and therefore emits more light at longer wavelengths.  https://photojournal.jpl.nasa.gov/catalog/PIA23792
Comet NEOWISE Discovery Images
This view of the belly and part of the head of comet 67P/Churyumov-Gerasimenko indicates several morphologically different regions as seen by ESA Rosetta spacecraft.
Distinct Terrains on Rosetta Comet
Comet NEOWISE is seen, upper left, before sunrise over Washington, Sunday, July 12, 2020. The comet was discovered by NASA’s Near-Earth Object Wide-field Infrared Survey Explorer, or NEOWISE, on March 27. Since then, the comet — called comet C/2020 F3 NEOWISE and nicknamed comet NEOWISE — has been spotted by several NASA spacecraft, including Parker Solar Probe, NASA’s Solar and Terrestrial Relations Observatory, the ESA/NASA Solar and Heliospheric Observatory, and astronauts aboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)
Comet NEOWISE Over Washington
Comet NEOWISE is seen before sunrise, upper left, over Washington, Sunday, July 12, 2020. The comet was discovered by NASA’s Near-Earth Object Wide-field Infrared Survey Explorer, or NEOWISE, on March 27. Since then, the comet — called comet C/2020 F3 NEOWISE and nicknamed comet NEOWISE — has been spotted by several NASA spacecraft, including Parker Solar Probe, NASA’s Solar and Terrestrial Relations Observatory, the ESA/NASA Solar and Heliospheric Observatory, and astronauts aboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)
Comet NEOWISE Over Washington
Comet NEOWISE was first observed by NASA NEOWISE spacecraft on Valentine Day, 2014. This heat-sensitive infrared image was made by combining six exposures taken by the NEOWISE mission of the newly discovered comet.
An Infrared portrait of Comet NEOWISE C/2014 C3
This image, taken by ESA Rosetta navigation camera, was taken from a distance of about 53 miles 86 kilometers from the center of Comet 67P/Churyumov-Gerasimenko on March 14, 2015. The image has a resolution of 24 feet (7 meters) per pixel and is cropped and processed to bring out the details of the comet's activity.  http://photojournal.jpl.nasa.gov/catalog/PIA19687
Rosetta Comet Marches On
This is a rare glance at the dark side of comet 67P/Churyumov-Gerasimenko. Light backscattered from dust particles in the comet coma reveals a hint of surface structures. This image was taken by OSIRIS, Rosetta scientific imaging system.
Rare Glance at Dark Side of Comet 67P/Churyumov-Gerasimenko
This graphic depicts the position of the Philae lander of the European Space Agency Rosetta mission in the context of topographic modeling of the surface of comet 67P/Churyumov-Gerasimenko nucleus.
Philae Lander Setting on Comet Surface
Four images taken by the ESA Rosetta spacecraft create a montage showing jets of dust and gas escaping from the nucleus of comet 67P/Churyumov–Gerasimenko.
Rosetta Comet Fires Its Jets
A jagged horizon of the nucleus of comet 67P/Churyumov-Gerasimenko appears in this image taken by the navigation camera on the ESA Rosetta spacecraft during the second half of October 2014.
Jagged Horizon on Rosetta Destination Comet
This image was taken by the Philae lander of the European Space Agency Rosetta mission when it was about 130 feet 40 meters above the surface of comet 67P/Churyumov-Gerasimenko during descent to the surface on Nov. 12, 2014.
Comet from 40 Meters
This image of the coma of comet 67P/Churyumov-Gerasimenko, seen with ESAS OSIRIS onboard the Rosetta spacecraft, shows the hazy circular structure to the right and center of the coma is an artifact due to overexposure of the nucleus.
Rosetta Comet: Imaging the Coma
This frame from an animated sequence shows the Rosetta mission Philae lander descending toward comet 67P/Churyumov-Gerasimenko not in frame on Nov. 12, 2014. The images are from the OSIRIS narrow-angle camera on the ESA Rosetta orbiter.
Descent to the Surface of a Comet
Comet C/2018 Y1 Iwamoto as imaged in multiple exposures of infrared light by the NEOWISE space telescope. The infrared images were taken on Feb. 25, 2019, when the comet was about 56 million miles, or 90 million kilometers, from Earth. C/2018 Y1 Iwamoto is a long-period comet originally from the Oort Cloud and coming in near the Sun for the first time in over 1,000 years.  Appearing as a string of red dots, this comet can be seen in a series of exposures captured by the spacecraft. Infrared light detected by the 3.4-micron channel is mapped to blue and green, while light from the 4.6-micron channel is mapped to red. In this image, stars show up as blue because they are hotter, whereas the cooler dust around the comet - with a temperature near the freezing point of water - glows red.   Movie available at https://photojournal.jpl.nasa.gov/catalog/PIA23165
Comet C/2018 Y1 Iwamoto
These radar images of comet P/2016 BA14 were taken on March 22, 2016, by scientists using an antenna of NASA Deep Space Network at Goldstone, CA. At the time, the comet was about 2.2 million miles 3.6 million kilometers from Earth.
Comet Scanned by NASA Radar
An annotated mosaic from the Rosetta spacecraft shows Site J, the primary landing site on comet 67P/Churyumov-Gerasimenko for the mission Philae lander.
Rosetta Comet Landing Site Close Up
This image of comet 67P/Churyumov-Gerasimenko was obtained on October 30, 2014 by the OSIRIS scientific imaging system on the Rosetta spacecraft. The right half is obscured by darkness.
Dark Side of Comet 67P/Churyumov-Gerasimenko
This view from the OSIRIS instrument onboard ESA Rosetta spacecraft shows the nucleus of comet 67P/Churyumov-Gerasimernko from a distance of 1,210 miles 1950 kilometers.
Comet 67P from 1,200 Miles Away
With the help of NASA Spitzer Space Telescope, astronomers have discovered that what was thought to be a large asteroid called Don Quixote is in fact a comet.
Spitzer Spies a Comet Coma and Tail
Comet 67P/Churyumov-Gerasimenko was imaged by ESA Rosetta spacecraft on July 20, 2014, from a distance of approximately 3,400 miles 5,500 kilometers. These three images were taken two hours apart.
Rosetta Approach Tripych: Comet 67P
Comet 67P/Churyumov-Gerasimenko by ESA Rosetta OSIRIS narrow-angle camera on August 3, 2014, from a distance of 177 miles 285 kilometers. The image resolution is 17 feet 5.3 meters per pixel.
Rosetta Comet from 177 Miles
Some relatively rough terrain on the nucleus of comet 67P/Churyumov-Gerasimenko appears in this image taken by the navigation camera on the European Space Agency Rosetta spacecraft in the second half of October 2014.
Rough Terrain on Rosetta Destination Comet
This image was taken by the Optical, Spectroscopic, and Infrared Remote Imaging System, Rosetta main onboard scientific imaging system, on Sept. 10, 2014. Jets of cometary activity can be seen along almost the entire body of the comet.
Rosetta Comet Spreads its Jets
A patch of relatively smooth ground on the nucleus surface of comet 67P/Churyumov-Gerasimenko appears in this image taken by the navigation camera on the European Space Agency Rosetta spacecraft in October 2014.
Smooth Ground on Rosetta Destination Comet
The Philae lander of the European Space Agency Rosetta mission is safely on the surface of Comet 67P/Churyumov-Gerasimenko, as these first two images from the lander CIVA camera confirm. One of the lander three feet can be seen in the foreground.
Welcome to a Comet, from Lander on Surface
This artist animation depicts one of the most widely accepted theories pertaining to the origin of comets. This image is courtesy of NASA Spitzer Science Center at the California Institute of Technology, Pasadena, Calif.
Genesis of a Comet Artist Concept
Captured March 12, 2010  The SOHO spacecraft captured a very bright, sungrazing comet as it rocketed towards the Sun (Mar. 12, 2010) and was vaporized. This comet is arguably the brightest comet that SOHO has observed since Comet McNaught in early 2007. The comet is believed to belong to the Kreutz family of comets that broke up from a much larger comet many hundreds of years ago. They are known to orbit close to the Sun. A coronal mass ejection (CME) burst away from the Sun during the bright comet’s approach.  Interestingly, a much smaller comet that preceded this one can be seen about half a day earlier on just about the identical route. And another pair of small comets followed the same track into the Sun after the bright one. Such a string of comets has never been witnessed before by SOHO. SOHO's C3 coronagraph instrument blocks out the Sun with an occulting disk; the white circle represents the size of the Sun. The planet Mercury can also be seen moving from left to right just beneath the Sun.  To learn more and to download the video and still images go here:  <a href="http://sohowww.nascom.nasa.gov/pickoftheweek/old/15mar2010/" rel="nofollow">sohowww.nascom.nasa.gov/pickoftheweek/old/15mar2010/</a>  Credit: NASA/GSFC/SOHO
Suicide Comet HD Video
This image showcases changes identified in high-resolution images of Comet 67P/Churyumov-Gerasimenko during more than two years of monitoring by ESA's Rosetta spacecraft.  The approximate locations of each feature are marked on the central context images. Dates of when the before and after images were taken are also indicated. Note that the orientation and resolution between image pairs may vary, therefore set arrows in each image point to the location of the changes, for guidance.  http://photojournal.jpl.nasa.gov/catalog/PIA21566
Comet 67P Changes
A short-lived outburst from comet 67P/Churyumov-Gerasimenko was captured by Rosetta's OSIRIS narrow-angle camera on July 29, 2015. The image at left was taken at 13:06 Greenwich Mean Time (GMT) (6:06 a.m. PDT), and does not show any visible signs of the jet. It is very strong in the middle image captured at 13:24 GMT (6:24 a.m. PDT). Residual traces of activity are only very faintly visible in the final image taken at 13:42 GMT (6:42 a.m. PDT).  The images were taken from a distance of 116 miles (186 kilometers) from the center of the comet. The jet is estimated to have a minimum speed of 33 feet per second (10 meters per second) and originates from a location on the comet's neck.  http://photojournal.jpl.nasa.gov/catalog/PIA19867
Rosetta Comet In Action Animation
This composite image was taken by the navigation camera during the close approach phase of Stardust's Jan 2, 2004 flyby of comet Wild 2. Several large depressed regions can be seen. Comet Wild 2 is about five kilometers (3.1 miles) in diameter. To create this image, a short exposure image showing tremendous surface detail was overlain on a long exposure image taken just 10 seconds later showing jets. Together, the images show an intensely active surface, jetting dust and gas streams into space and leaving a trail millions of kilometers long.   http://photojournal.jpl.nasa.gov/catalog/PIA05578
Comet Wild 2 - Jet Release
These radar images of comet P/2016 BA14 were taken on March 23, 2016, by scientists using an antenna of NASA Deep Space Network at Goldstone, California. At the time, the comet was about 2.2 million miles 3.6 million kilometers from Earth.
Comet Frozen In Time by NASA Radar
This image was taken by the Optical, Spectroscopic, and Infrared Remote Imaging System, Rosetta main onboard scientific imaging system, on Sept. 10, 2014. Jets of cometary activity can be seen along almost the entire body of the comet.  http://photojournal.jpl.nasa.gov/catalog/PIA18886
Rosetta Comet Spreads its Jets
On January 2, 2004 NASA's Stardust spacecraft made a close flyby of comet Wild 2 (pronounced "Vilt-2"). Among the equipment the spacecraft carried on board was a navigation camera. This is the 34th of the 72 images taken by Stardust's navigation camera during close encounter. The exposure time was 10 milliseconds. The two frames are actually of 1 single exposure. The frame on the left depicts the comet as the human eye would see it. The frame on the right depicts the same image but "stretched" so that the faint jets emanating from Wild 2 can be plainly seen. Comet Wild 2 is about five kilometers (3.1 miles) in diameter.   http://photojournal.jpl.nasa.gov/catalog/PIA05571
Comet Wild 2 Up Close and Personal
This mosaic of images from the navigation camera on the ESA Rosetta spacecraft shows the nucleus of comet 67P/Churyumov-Gerasimenko as it appeared at in the early morning, Universal Coordinated Time, of Dec. 17, 2014 evening of Dec. 16, PST.
December 2014 View of Comet 67P/Churyumov-Gerasimenko
The Philae lander of Europe Rosetta mission has returned the first panoramic image from the surface of a comet. The unprocessed panorama from the lander CIVA-P camera shows a 360-degree view around the point of final touchdown.
First Panoramic View from Comet Lander
This graphic depicts the position of the Philae lander of the European Space Agency Rosetta mission, and a nearby cliff photographed by the lander, in the context of topographic modeling of the surface of comet 67P/Churyumov-Gerasimenko nucleus.
Philae Lander Setting on Comet, with Cliff-Image Inset
From the location where it came to rest after bounces, the Philae lander of the European Space Agency Rosetta mission captured this view of a cliff on the nucleus of comet 67P/Churyumov-Gerasimenko. The feature is called Perihelion Cliff.
Philae Lander View of Perihelion Cliff on Comet Surface
This image shows the most recent observations of the 2-mile-wide 4-kilometer-wide comet 67P/Churyumov-Gerasimenko, which is the upcoming target of the European Space Agency Rosetta mission.
Comet 67P/Churyumov-Gerasimenko on Oct. 5, 2013
This mosaic of images from the navigation camera on the European Space Agency Rosetta spacecraft shows the nucleus of comet 67P/Churyumov-Gerasimenko as it appeared at 5 a.m. UTC on Dec. 17, 2014 9 p.m. PST on Dec. 16.
December 2014 View of Rosetta Destination Comet
Images of comet 67P/Churyumov-Gerasimenko taken on July 14, 2014, by the OSIRIS imaging system aboard ESA Rosetta spacecraft have allowed scientists to create this three-dimensional shape model of the nucleus.
Rotating Shape Model of Rosetta Comet Target
This image of comet 67P/Churyumov-Gerasimenko marks the first touchdown point of the Philae lander of the European Space Agency Rosetta mission. The image was taken by on Sept. 14, 2104, nearly two months before Philae Nov. 12 landing.
First Touchdown Site of Comet Lander
The International Space Station, with a crew of five onboard, is seen in this 10 second exposure above comet NEOWISE, Saturday, July 18, 2020 from Keys Gap, W.Va. The comet was discovered by NASA’s Near-Earth Object Wide-field Infrared Survey Explorer, or NEOWISE, on March 27. Since then, the comet — called comet C/2020 F3 NEOWISE and nicknamed comet NEOWISE — has been spotted by several NASA spacecraft, including Parker Solar Probe, NASA’s Solar and Terrestrial Relations Observatory, the ESA/NASA Solar and Heliospheric Observatory, and astronauts aboard the International Space Station. Onboard the International Space Station are Expedition 63 NASA astronauts Chris Cassidy, Douglas Hurley, Robert Behnken, and Roscosmos cosmonauts Anatoly Ivanishin and Ivan Vagner.  Photo Credit: (NASA/Bill Ingalls)
Comet NEOWISE and ISS
Several sites of cliff collapse on comet 67P/Churyumov-Gerasimenko were identified during Rosetta's mission. The yellow arrows mark the fractures where the detachment occurred. The collapsed sections are about 50 feet (15 meters) long for the left-hand section, and 30 feet (9 meters) for the right-hand section. Additional images taken from greater distances suggest the collapse occurred between May and December 2015.  The images were taken by Rosetta's OSIRIS camera on Dec. 2, 2014 (left), and March 12, 2016 (right), with resolutions of 1.6 feet (0.5 meters) per pixel and 1 foot (0.3 meters) per pixel, respectively.  http://photojournal.jpl.nasa.gov/catalog/PIA21564
Cliff Collapses on Rosetta Comet
Comet NEOWISE passing over the Little Joe II rocket at NASA Johnson Space Center’s Rocket Park on July 22nd, 2020.
Comet NEOWISE Over Rocket Park
Hubble measured the size, shape and rotational period of the Rosetta mission backup target, comet 67P/Churyumov-Gerasimenko 67P/C-G.
3-D Models of Comet 67P/Churyumov-Gerasimenko Nucleus
The Philae lander of the European Space Agency Rosetta mission captured this view during its first bounce after hitting the surface of comet 67P/Churyumov-Gerasimenko on Nov. 12, 2014, with blurring as a result of the lander own motion. The image from
Comet Lander View During First Bounce
This view shows Comet 67P/Churyumov-Gerasimenko as seen by the OSIRIS wide-angle camera on ESA's Rosetta spacecraft on September 29, 2016, when Rosetta was at an altitude of 14 miles (23 kilometers).  The European Space Agency's (ESA) Rosetta mission will come to a dramatic end on Friday, Sept. 30, with a controlled touchdown of the spacecraft on a region of comet 67P/Churyumov-Gerasimenko known for active pits that spew comet dust into space. Confirmation of the end of mission is expected at about 4:20 a.m. PDT (7:20 a.m. EDT). ESA is ending the mission due to the spacecraft's ever-increasing distance from the sun, which has resulted in significantly reduced solar power with which to operate the vehicle and its instruments.  http://photojournal.jpl.nasa.gov/catalog/PIA21068
Farewell Rosetta: ESA Mission to End on Comet Surface
This observation from ESA Rosetta spacecraft shows that comet 67P/Churyumov-Gerasimenko has a two-part shape. The image on the left is from OSIRIS; the image on the right is enhanced with interpolated data.
Rosetta Mission Destination: Comet 67P/Churnyumov-Gerasimenko
Comets and Enceladus - Similar Chemistry
Comets and Enceladus - Similar Chemistry
Anatomy of a Torn Comet
Anatomy of a Torn Comet
This composite NASA Hubble Space Telescope Image captures the positions of comet Siding Spring and Mars in a never-before-seen close passage of a comet by the Red Planet, which happened at 2:28 p.m. EDT October 19, 2014. The comet passed by Mars at approximately 87,000 miles (about one-third of the distance between Earth and the Moon). At that time, the comet and Mars were approximately 149 million miles from Earth.  The comet image shown here is a composite of Hubble exposures taken between Oct. 18, 8:06 a.m. EDT to Oct. 19, 11:17 p.m. EDT. Hubble took a separate photograph of Mars at 10:37 p.m. EDT on Oct. 18.  The Mars and comet images have been added together to create a single picture to illustrate the angular separation, or distance, between the comet and Mars at closest approach. The separation is approximately 1.5 arc minutes, or one-twentieth of the angular diameter of the full Moon. The background starfield in this composite image is synthesized from ground-based telescope data provided by the Palomar Digital Sky Survey, which has been reprocessed to approximate Hubble’s resolution. The solid icy comet nucleus is too small to be resolved in the Hubble picture. The comet’s bright coma, a diffuse cloud of dust enshrouding the nucleus, and a dusty tail, are clearly visible.  This is a composite image because a single exposure of the stellar background, comet Siding Spring, and Mars would be problematic. Mars is actually 10,000 times brighter than the comet, and so could not be properly exposed to show detail in the Red Planet. The comet and Mars were also moving with respect to each other and so could not be imaged simultaneously in one exposure without one of the objects being motion blurred. Hubble had to be programmed to track on the comet and Mars separately in two different observations.   The images were taken with Hubble’s Wide Field Camera 3.  Credit: NASA, ESA, PSI, JHU/APL, STScI/AURA  Credit: NASA, ESA, PSI, JHU/APL, STScI/AURA
Comet Siding Spring Seen Next to Mars
The descent of its comet lander Philae was captured by ESA Rosetta spacecraft main camera as the lander approached -- and then rebounded off -- the comet surface.
Rosetta Lander Captured Before/After Bounce
Dr. Michael A'Hearn, Principal Investigator, EPOXI Comet Encounter Mission, speaks during a symposium commemorating a quarter-century of comet discoveries, Friday, Sept. 10, 2010, in the Knight studio at the Newseum in Washington. The International Sun-Earth Explorer-3 (ISEE-3) spacecraft flew past the comet Giacobini-Zinner on Sept. 11, 1985 which established a foundation of discoveries that continue today. Photo Credit: (NASA/Paul E. Alers)
First Comet Encounter
During its one-year mission, NASA Wide-field Infrared Survey Explorer, mapped the entire sky in infrared light. Among the multitudes of astronomical bodies that have been discovered by the NEOWISE portion of the WISE mission are 20 comets.
Comets WISE -- A Family Portrait
On clear nights in January 2015, comet C/2014 Q2 Lovejoy is visible in the Taurus region of the sky to observers using binoculars. This chart indicates where to look for it on different dates during the month.
Finder Chart for Viewing Comet C/2014 Q2 Lovejoy
Sungrazing comets are a special class of comets that come very close to the sun at their nearest approach, a point called perihelion. To be considered a sungrazer, a comet needs to get within about 850,000 miles from the sun at perihelion. Many come even closer, even to within a few thousand miles.  Being so close to the sun is very hard on comets for many reasons. They are subjected to a lot of solar radiation which boils off their water or other volatiles. The physical push of the radiation and the solar wind also helps form the tails. And as they get closer to the sun, the comets experience extremely strong tidal forces, or gravitational stress. In this hostile environment, many sungrazers do not survive their trip around the sun. Although they don't actually crash into the solar surface, the sun is able to destroy them anyway.  Many sungrazing comets follow a similar orbit, called the Kreutz Path, and collectively belong to a population called the Kreutz Group. In fact, close to 85% of the sungrazers seen by the SOHO satellite are on this orbital highway. Scientists think one extremely large sungrazing comet broke up hundreds, or even thousands, of years ago, and the current comets on the Kreutz Path are the leftover fragments of it. As clumps of remnants make their way back around the sun, we experience a sharp increase in sungrazing comets, which appears to be going on now. Comet Lovejoy, which reached perihelion on December 15, 2011 is the best known recent Kreutz-group sungrazer. And so far, it is the only one that NASA's solar-observing fleet has seen survive its trip around the sun.  Comet ISON, an upcoming sungrazer with a perihelion of 730,000 miles on November 28, 2013, is not on the Kreutz Path. In fact, ISON's orbit suggests that it may gain enough momentum to escape the solar system entirely, and never return. Before it does so, it will pass within about 40 million miles from Earth on December 26th.   More information on this topic available at: <a href="http://www.nasa.gov/content/goddard/timeline-of-comet-ison-s-dangerous-journey/" rel="nofollow">www.nasa.gov/content/goddard/timeline-of-comet-ison-s-dan...</a>  Credit: NASA's Goddard Space Flight Center  <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/NASA_GoddardPix" 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://instagram.com/nasagoddard?vm=grid" rel="nofollow">Instagram</a></b>
What is a Sungrazing Comet? [hd video]
Taken on 19 Nov. 2013, this image shows a composite &quot;stacked&quot; image of comet ISON. These five stacked images of 10 seconds each were taken with the 20&quot; Marshall Space Flight Center telescope in New Mexico. This technique allows the comet's sweeping tail to emerge with more detail.  Credit: NASA/MSFC/MEO/Cameron McCarty  --------  More details on Comet ISON:  Comet ISON began its trip from the Oort cloud region of our solar system and is now travelling toward the sun. The comet will reach its closest approach to the sun on Thanksgiving Day -- 28 Nov 2013 -- skimming just 730,000 miles above the sun's surface. If it comes around the sun without breaking up, the comet will be visible in the Northern Hemisphere with the naked eye, and from what we see now, ISON is predicted to be a particularly bright and beautiful comet.  Catalogued as C/2012 S1, Comet ISON was first spotted 585 million miles away in September 2012. This is ISON's very first trip around the sun, which means it is still made of pristine matter from the earliest days of the solar system’s formation, its top layers never having been lost by a trip near the sun. Comet ISON is, like all comets, a dirty snowball made up of dust and frozen gases like water, ammonia, methane and carbon dioxide -- some of the fundamental building blocks that scientists believe led to the formation of the planets 4.5 billion years ago.   NASA has been using a vast fleet of spacecraft, instruments, and space- and Earth-based telescope, in order to learn more about this time capsule from when the solar system first formed.   The journey along the way for such a sun-grazing comet can be dangerous. A giant ejection of solar material from the sun could rip its tail off. Before it reaches Mars -- at some 230 million miles away from the sun -- the radiation of the sun begins to boil its water, the first step toward breaking apart. And, if it survives all this, the intense radiation and pressure as it flies near the surface of the sun could destroy it altogether.   This collection of images show ISON throughout that journey, as scientists watched to see whether the comet would break up or remain intact.    The comet reaches its closest approach to the sun on Thanksgiving Day -- Nov. 28, 2013 -- skimming just 730,000 miles above the sun’s surface. If it comes around the sun without breaking up, the comet will be visible in the Northern Hemisphere with the naked eye, and from what we see now, ISON is predicted to be a particularly bright and beautiful comet.   ISON stands for International Scientific Optical Network, a group of observatories in ten countries who have organized to detect, monitor, and track objects in space. ISON is managed by the Keldysh Institute of Applied Mathematics, part of the Russian Academy of Sciences.  <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/NASA_GoddardPix" rel="nofollow">Twitter</a></b>  <b>Like us on &lt;a href=&quot;http://www.facebook.com/pages/Greenbelt-MD/NASA-Goddard/39501</b>
Comet ISON Enhanced
This image shows the comet Wild 2, which NASA's Stardust spacecraft flew by on Jan. 2, 2004. This image is the closest short exposure of the comet, taken at an11.4-degree phase angle, the angle between the camera, comet and the Sun.  http://photojournal.jpl.nasa.gov/catalog/PIA06285
Wild 2 Close Look
The Oort Cloud comet, called C/2023 A3 Tsuchinshan-ATLAS, passes over Southeast Louisiana near New Orleans, home of NASA’s Michoud Assembly Facility, Sunday, Oct. 13, 2024. The comet is making its first appearance in documented human history; it was last seen in the night sky 80,000 years ago. The Tsuchinshan-ATLAS comet made its first close pass by Earth in mid-October and will remain visible to viewers in the Northern Hemisphere just between the star Arcturus and planet Venus through early November.
Ancient Comet Spotted Over Southeast Louisiana Near NASA Michoud
NASA's Solar TErrestrial Relations Observatory, STEREO has observed the recently discovered Comet Jacques as it passed by its nearest approach to the Sun (July 1-6, 2014). The wide field instrument on board STEREO (Ahead) showed the comet with its elongated tail being stretched and pummeled by the gusty solar wind streaming from the Sun. Also visible near the center of the image is the bright planet Venus. The Sun is just out of the field of view to the right. Comet Jacques is traveling through space at about 180,000 km per hour (110,000 mph). It may brighten enough to be seen with the naked eye.   High res still here: <a href="https://www.flickr.com/photos/gsfc/14710024276/">www.flickr.com/photos/gsfc/14710024276/</a>  Download original file: <a href="http://sohowww.nascom.nasa.gov/pickoftheweek/old/11jul2014/" rel="nofollow">sohowww.nascom.nasa.gov/pickoftheweek/old/11jul2014/</a>  Credit: NASA/Goddard/STEREO  <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://instagram.com/nasagoddard?vm=grid" rel="nofollow">Instagram</a></b>
Comet Jacques Approaches the Sun
This artist concept of the Rosetta mission Philae lander on the surface of comet 67P/Churyumov-Gerasimenko, is from an animation showing the upcoming deployment of Philae and its subsequent science operations on the surface of the comet.  http://photojournal.jpl.nasa.gov/catalog/PIA18891
Philae Descent and Science of the Surface
On April 1, 2017, comet 41P will pass closer than it normally does to Earth, giving observers with binoculars or a telescope a special viewing opportunity. Comet hunters in the Northern Hemisphere should look for it near the constellations Draco and Ursa Major, which the Big Dipper is part of.  Whether a comet will put on a good show for observers is notoriously difficult to predict, but 41P has a history of outbursts, and put on quite a display in 1973. If the comet experiences similar outbursts this time, there’s a chance it could become bright enough to see with the naked eye. The comet is expected to reach perihelion, or its closest approach to the sun, on April 12.  A member of the Jupiter family of comets, 41P makes a trip around the sun every 5.4 years, coming relatively close to Earth on some of those trips. On this approach, the comet will pass our planet at a distance of about 13 million miles (0.14 astronomical units), or about 55 times the distance from Earth to the moon. This is the comet’s closest approach to Earth in more than 50 years and perhaps more than a century.  Read more: <a href="https://go.nasa.gov/2nLNzes" rel="nofollow">go.nasa.gov/2nLNzes</a>  Photo caption: In this image taken March 24, 2017, comet 41P/Tuttle-Giacobini-Kresák is shown moving through a field of faint galaxies in the bowl of the Big Dipper. On April 1, the comet will pass by Earth at a distance of about 13 million miles (0.14 astronomical units), or 55 times the distance from Earth to the moon; that is a much closer approach than usual for this Jupiter-family comet.  Photo credit: Image copyright Chris Schur©, used with permission  <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>
"April Fool’s Day" comet to pass by Earth
Date: 8 Nov 2013 - Comet ISON shines in this five-minute exposure taken at NASA's Marshall Space Flight Center on Nov. 8, 2013.. The image was captured using a color CCD camera attached to a 14&quot; telescope located at Marshall. At the time of this picture, comet ISON was 97 million miles from Earth, moving ever closer toward the sun.  Credit: NASA/MSFC/Aaron Kingery  --------  More details on Comet ISON:  Comet ISON began its trip from the Oort cloud region of our solar system and is now travelling toward the sun. The comet will reach its closest approach to the sun on Thanksgiving Day -- 28 Nov 2013 -- skimming just 730,000 miles above the sun's surface. If it comes around the sun without breaking up, the comet will be visible in the Northern Hemisphere with the naked eye, and from what we see now, ISON is predicted to be a particularly bright and beautiful comet.  Catalogued as C/2012 S1, Comet ISON was first spotted 585 million miles away in September 2012. This is ISON's very first trip around the sun, which means it is still made of pristine matter from the earliest days of the solar system’s formation, its top layers never having been lost by a trip near the sun. Comet ISON is, like all comets, a dirty snowball made up of dust and frozen gases like water, ammonia, methane and carbon dioxide -- some of the fundamental building blocks that scientists believe led to the formation of the planets 4.5 billion years ago.   NASA has been using a vast fleet of spacecraft, instruments, and space- and Earth-based telescope, in order to learn more about this time capsule from when the solar system first formed.   The journey along the way for such a sun-grazing comet can be dangerous. A giant ejection of solar material from the sun could rip its tail off. Before it reaches Mars -- at some 230 million miles away from the sun -- the radiation of the sun begins to boil its water, the first step toward breaking apart. And, if it survives all this, the intense radiation and pressure as it flies near the surface of the sun could destroy it altogether.   This collection of images show ISON throughout that journey, as scientists watched to see whether the comet would break up or remain intact.    The comet reaches its closest approach to the sun on Thanksgiving Day -- Nov. 28, 2013 -- skimming just 730,000 miles above the sun’s surface. If it comes around the sun without breaking up, the comet will be visible in the Northern Hemisphere with the naked eye, and from what we see now, ISON is predicted to be a particularly bright and beautiful comet.   ISON stands for International Scientific Optical Network, a group of observatories in ten countries who have organized to detect, monitor, and track objects in space. ISON is managed by the Keldysh Institute of Applied Mathematics, part of the Russian Academy of Sciences.  <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/NASA_GoddardPix" 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://instagram.com/nasagoddard?vm=grid" rel="nofollow">Instagram</a></b>
Comet ISON Passes Through Virgo
This is an artist's concept depicting a view of comet Wild 2 as seen from NASA's Stardust spacecraft during its flyby of the comet on Jan. 2, 2004.  http://photojournal.jpl.nasa.gov/catalog/PIA06283
Wild 2: If You Were There
Dr. Anita Cochran, Assistant Director, McDonald Observatory at the University of Texas-Austin, speaks during a symposium commemorating a quarter-century of comet discoveries, Friday, Sept. 10, 2010, in the Knight studio at the Newseum in Washington. The International Sun-Earth Explorer-3 (ISEE-3) spacecraft flew past the comet Giacobini-Zinner on Sept. 11, 1985 which established a foundation of discoveries that continue today. Photo Credit: (NASA/Paul E. Alers)
First Comet Encounter
Dr. James L. Green, Director of Planetary Science at NASA, speaks during a symposium commemorating a quarter-century of comet discoveries, Friday, Sept. 10, 2010, in the Knight studio at the Newseum in Washington. The International Sun-Earth Explorer-3 (ISEE-3) spacecraft flew past the comet Giacobini-Zinner on Sept. 11, 1985 which established a foundation of discoveries that continue today. Photo Credit: (NASA/Paul E. Alers)
First Comet Encounter
Kjell Stakkestad, President and CEO of KinetX Inc., speaks during a symposium commemorating a quarter-century of comet discoveries, Friday, Sept. 10, 2010, in the Knight studio at the Newseum in Washington. The International Sun-Earth Explorer-3 (ISEE-3) spacecraft flew past the comet Giacobini-Zinner on Sept. 11, 1985 which established a foundation of discoveries that continue today. Photo Credit: (NASA/Paul E. Alers)
First Comet Encounter
This movie from NASA’s STEREO spacecraft's Heliospheric Imager shows Comet ISON, Mercury, Comet Encke and Earth over a five-day period from Nov. 20 to Nov. 25, 2013. The sun sits right of the field of view of this camera. Comet ISON, which will round the sun on Nov. 28, is what's known as a sungrazing comet, due to its close approach.  Foreshortening or the angle at which these images were obtained make Earth appear as if it is closer to the sun than Mercury. If you look closely you will also see a dimmer and smaller comet Encke near comet ISON.    A comet’s journey through the solar system is perilous and violent. A giant ejection of solar material from the sun could rip its tail off. Before it reaches Mars -- at some 230 million miles away from the sun -- the radiation of the sun begins to boil its water, the first step toward breaking apart. And, if it survives all this, the intense radiation and pressure as it flies near the surface of the sun could destroy it altogether.   Even if the comet does not survive, tracking its journey will help scientists understand what the comet is made of, how it reacts to its environment, and what this explains about the origins of the solar system. Closer to the sun, watching how the comet and its tail interact with the vast solar atmosphere can teach scientists more about the sun itself.   Image Credit: NASA/STEREO  <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/NASA_GoddardPix" 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://instagram.com/nasagoddard?vm=grid" rel="nofollow">Instagram</a></b>
Comet ISON Approaching the Sun [hd video]
Comet Hyakutake C/1996 B2
Comet Hyakutake C/1996 B2
Hubble Images of Comet Hale-Bopp
Hubble Images of Comet Hale-Bopp
Comet Impact Into Jupiter Artist Concept
Comet Impact Into Jupiter Artist Concept
This movie shows Comet ISON orbiting around the sun – represented by the white circle -- on Nov. 28, 2013. ISON looks smaller as it streams away, but scientists believe its nucleus may still be intact. The video covers Nov. 27, 2013, 3:30 p.m. EST to Nov. 29, 2013, 8:30 a.m. EST.  Continuing a history of surprising behavior, material from Comet ISON appeared on the other side of the sun on the evening on Nov. 28, 2013, despite not having been seen in observations during its closest approach to the sun. The question remains whether it is merely debris from the comet, or if some portion of the comet's nucleus survived, but late-night analysis from scientists with NASA's Comet ISON Observing Campaign suggest that there is at least a small nucleus intact.  Credit: ESA/NASA/SOHO/Jhelioviewer  <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/NASA_GoddardPix" 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://instagram.com/nasagoddard?vm=grid" rel="nofollow">Instagram</a></b>
Comet ISON May Have Survived
On October 19, Comet Siding Spring will pass within 88,000 miles of Mars – just one third of the distance from the Earth to the Moon! Traveling at 33 miles per second and weighing as much as a small mountain, the comet hails from the outer fringes of our solar system, originating in a region of icy debris known as the Oort cloud. Comets from the Oort cloud are both ancient and rare. Since this is Comet Siding Spring’s first trip through the inner solar system, scientists are excited to learn more about its composition and the effects of its gas and dust on the Mars upper atmosphere. NASA will be watching closely before, during, and after the flyby with its entire fleet of Mars orbiters and rovers, along with the Hubble Space Telescope and dozens of instruments on Earth. The encounter is certain to teach us more about Oort cloud comets, the Martian atmosphere, and the solar system’s earliest ingredients.  Learn more: <a href="https://www.youtube.com/watch?v=FG4KsatjFeI" rel="nofollow">www.youtube.com/watch?v=FG4KsatjFeI</a>  Credit: NASA’s Goddard Space Flight Center    <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://instagram.com/nasagoddard?vm=grid" rel="nofollow">Instagram</a></b>
Comet Siding Spring Mars Flyby
Release Date: November 25, 2013  MESSENGER image of comet C/2012 S1 (ISON) during its closest approach to Mercury. At that time, ISON was approximately 22.5 million miles (36.2 million kilometers) from MESSENGER and 42.1 million miles (67.8 million kilometers) from the Sun. The image is 7° by 4.7° in size and has been slightly magnified and smoothed to enhance the faint tail of the comet. The tail was oriented at an angle to MESSENGER at the time and is foreshortened in this image; however, some faint structure can still be seen.  MESSENGER's cameras have been acquiring targeted observations (watch an animation here) of Encke since October 28 and ISON since October 26, although the first faint detections didn't come until early November. During the closest approach of each comet to Mercury, the Mercury Atmospheric and Surface Composition Spectrometer (MASCS) and X-Ray Spectrometer (XRS) instruments also targeted the comets. Observations of ISON conclude on November 26, when the comet passes too close to the Sun, but MESSENGER will continue to monitor Encke with both the imagers and spectrometers through early December. Read this mission news story for more details.  The MESSENGER spacecraft is the first ever to orbit the planet Mercury, and the spacecraft's seven scientific instruments and radio science investigation are unraveling the history and evolution of the Solar System's innermost planet. During the first two years of orbital operations, MESSENGER acquired over 150,000 images and extensive other data sets. MESSENGER is capable of continuing orbital operations until early 2015.  Date acquired: 01:54:30 UTC on November 20, 2013 Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)  Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington/Southwest Research Institute  <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/NASA_GoddardPix" 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>
A Tale of Two Comets: ISON
This visitor from deep space, seen here by NASA Wide-field Infrared Survey Explorer, is comet Hartley 2, the destination for NASA EPOXI mission. The comet tail is seen here as a fuzzy streak to the right of the comet.
Icy Visitor from Beyond
Date: 19 Nov 2013  Comet ISON shows off its tail in this three-minute exposure taken on 19 Nov. 2013 at 6:10 a.m. EST, using a 14-inch telescope located at the Marshall Space Flight Center. The comet is just nine days away from its close encounter with the sun; hopefully it will survive to put on a nice show during the first week of December. The star images are trailed because the telescope is tracking on the comet, which is now exhibiting obvious motion with respect to the background stars over a period of minutes.  At the time of this image, Comet ISON was some 44 million miles from the sun -- and 80 million miles from Earth -- moving at a speed of 136,700 miles per hour.  Credit: NASA/MSFC/Aaron Kingery  --------  More details on Comet ISON:  Comet ISON began its trip from the Oort cloud region of our solar system and is now travelling toward the sun. The comet will reach its closest approach to the sun on Thanksgiving Day -- 28 Nov 2013 -- skimming just 730,000 miles above the sun's surface. If it comes around the sun without breaking up, the comet will be visible in the Northern Hemisphere with the naked eye, and from what we see now, ISON is predicted to be a particularly bright and beautiful comet.  Catalogued as C/2012 S1, Comet ISON was first spotted 585 million miles away in September 2012. This is ISON's very first trip around the sun, which means it is still made of pristine matter from the earliest days of the solar system’s formation, its top layers never having been lost by a trip near the sun. Comet ISON is, like all comets, a dirty snowball made up of dust and frozen gases like water, ammonia, methane and carbon dioxide -- some of the fundamental building blocks that scientists believe led to the formation of the planets 4.5 billion years ago.   NASA has been using a vast fleet of spacecraft, instruments, and space- and Earth-based telescope, in order to learn more about this time capsule from when the solar system first formed.   The journey along the way for such a sun-grazing comet can be dangerous. A giant ejection of solar material from the sun could rip its tail off. Before it reaches Mars -- at some 230 million miles away from the sun -- the radiation of the sun begins to boil its water, the first step toward breaking apart. And, if it survives all this, the intense radiation and pressure as it flies near the surface of the sun could destroy it altogether.   This collection of images show ISON throughout that journey, as scientists watched to see whether the comet would break up or remain intact.    The comet reaches its closest approach to the sun on Thanksgiving Day -- Nov. 28, 2013 -- skimming just 730,000 miles above the sun’s surface. If it comes around the sun without breaking up, the comet will be visible in the Northern Hemisphere with the naked eye, and from what we see now, ISON is predicted to be a particularly bright and beautiful comet.   ISON stands for International Scientific Optical Network, a group of observatories in ten countries who have organized to detect, monitor, and track objects in space. ISON is managed by the Keldysh Institute of Applied Mathematics, part of the Russian Academy of Sciences.  <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/NASA_GoddardPix" rel="nofollow">Twitter</a></b>  <b>Like us on &lt;a href=&quot;http://www.facebook.com/pages/Greenbelt-MD/NASA-Goddard/39501</b>
Comet ISON Streaks Toward the Sun
Steve Chesley, Stardust NExT co-investigator, the Jet Propulsion Laboratory, holds up a model of Comet Tempel 1 during a news briefing, Wednesday, Jan. 19, 2011, at NASA Headquarters in Washington. On Feb. 14, 2011 NASA's Stardust-NExT (New Exploration of Tempel 1) mission will encounter Comet Tempel 1, providing a unique opportunity to measure the dust properties which will also provide a comparison between two observations of a single comet, Tempel 1, taken before and after a single orbital pass around the sun. Photo Credit: (NASA/Paul E. Alers)
Stardust NExT Comet Redezvous
Image taken by NASA EPOXI mission spacecraft during its flyby of comet Hartley 2 on Nov. 4, 2010. The spacecraft came within about 700 kilometers 435 miles of the comet nucleus at the time of closest approach.
Flight of the Comet
These pictures of comet Tempel 1 were taken by NASA Hubble Space Telescope. They show the comet before and after it ran over NASA Deep Impact probe.
Hubble Witnesses Comet Crash
NASA Spitzer Space Telescope captured this picture of comet Holmes in March 2008, five months after the comet suddenly erupted and brightened a millionfold overnight.
Anatomy of a Busted Comet
This close-up view of comet Hartley 2 was taken as NASA EPOXI mission approached the comet at 6:59 a.m. PDT 9:59 a.m. EDT.
Almost There at Comet Hartley 2
This close-up view of comet Hartley 2 was taken as NASA EPOXI mission approached the comet at 6:58 a.m. PDT 9:58 a.m. EDT.
Closing in on Comet Hartley 2
This image from NASA Wide-field Infrared Survey Explorer features comet 65/P Gunn. Comets are balls of dust and ice left over from the formation of the solar system. The comet tail is seen here in red trailing off to the right of the comet nucleus.
WISE Catches Comet 65P/Gunn