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
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
MARCH 27, 2014: Comet Siding Spring is plunging toward the Sun along a roughly 1-million-year orbit. The comet, discovered in 2013, was within the radius of Jupiter's orbit when the Hubble Space Telescope photographed it on March 11, 2014. Hubble resolves two jets of dust coming from the solid icy nucleus. These persistent jets were first seen in Hubble pictures taken on Oct. 29, 2013. The feature should allow astronomers to measure the direction of the nucleus's pole, and hence, rotation axis. The comet will make its closest approach to our Sun on Oct. 25, 2014, at a distance of 130 million miles, well outside Earth's orbit. On its inbound leg, Comet Siding Spring will pass within 84,000 miles of Mars on Oct. 19, 2014, which is less than half the Moon's distance from Earth. The comet is not expected to become bright enough to be seen by the naked eye.  Credit: NASA, ESA, and J.-Y. Li (Planetary Science 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/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>
Hubble's View of Comet Siding Spring
This image from an animiation of comet C/2013 A1 Siding Spring were taken by the Mast Camera Mastcam on NASA Curiosity Mars rover as the comet passed near the red planet on Oct. 19, 2014.
Mars Curiosity Rover Views Comet Siding Spring
NASA NEOWISE mission captured images of Comet C/2013 A1 Siding Spring. The infrared pictures reveal a comet that is active and very dusty.
NEOWISE Spies Comet C/2013 A1 Siding Spring
NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft obtained this ultraviolet image of hydrogen surrounding comet Siding Spring on Friday, Oct. 17, two days before the comet’s closest approach to Mars. The Imaging Ultraviolet Spectrograph (IUVS) instrument imaged the comet at a distance of 5.3 million miles (8.5 million kilometers).  The image shows sunlight that has been scattered by atomic hydrogen, and is shown as blue in this false-color representation. Comets are surrounded by a huge cloud of atomic hydrogen because water (H2O) vaporizes from the icy nucleus, and solar ultraviolet light breaks it apart into hydrogen and oxygen. Hydrogen atoms scatter solar ultraviolet light, and it was this light that was imaged by the IUVS. Two observations were combined to create this image, after removing the foreground signal that results from sunlight being scattered from hydrogen surrounding Mars.  The bulk of the scattered sunlight shows a cloud that was about a half degree across on the “sky” background, comparable in size to Earth’s moon as seen from Earth.  Hydrogen was detected to as far as 93,000 miles (150,000 kilometers) away from the comet’s nucleus. The distance is comparable to the distance of the comet from Mars at its closest approach. Gas from the comet is likely to have hit Mars, and would have done so at a speed of 125,000 mph (56 kilometers/second. This gas may have disturbed the Mars atmosphere. Credit: Laboratory for Atmospheric and Space Physics, University of Colorado; NASA <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>
MAVEN Ultraviolet Image of Comet Siding Spring’s Hydrogen Coma
NASA MAVEN spacecraft obtained this ultraviolet image of hydrogen surrounding comet Siding Spring on Oct. 17, 2014, two days before the comet closest approach to Mars.
MAVEN Ultraviolet Image of Comet Siding Spring Hydrogen Coma
This synthesized composite of NASA Hubble Space Telescope images captures the positions of comet Siding Spring and Mars in a never-before-seen close passage of a comet by the Red Planet.
Close Encounters: Comet Siding Spring Seen Next to Mars Synthesized Image
NASA NEOWISE mission detected comet C/2013 A1 Siding Spring on July 28, 2014, less than three months before this comet close flyby of Mars on Oct. 19.
NEOWISE Spies Comet C/2013 A1 Siding Spring a Second Time
Comet Siding Spring will have a close approach to Mars on Oct. 19, 2014. This artist concept shows people in the Southern Hemisphere where to look for Mars in the night sky. Mars and the comet may be visible with binoculars.
View of Comet Siding Spring from Southern Hemisphere Artist Concept
This artist concept shows NASA Mars orbiters lining up behind the Red Planet for their duck and cover maneuver to shield them from comet dust that may result from the close flyby of comet Siding Spring C/2013 A1 on Oct. 19, 2014.
Mars Orbiters Duck and Cover for Comet Siding Spring Flyby Artist Concept
Carey Lisse, senior astrophysicist, Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland gives remarks during a media briefing where he and other panelists outlined how space and Earth-based assets will be used to image and study comet Siding Spring during its Sunday, Oct. 19 flyby of Mars, Thursday, Oct. 9, 2014 at NASA Headquarters in Washington.  Photo Credit: (NASA/Joel Kowsky)
Mars Comet Encounter Briefing
Jim Green, director, Planetary Science Division, NASA Headquarters, Washington gives remarks during a media briefing where he and other panelists outlined how space and Earth-based assets will be used to image and study comet Siding Spring during its Sunday, Oct. 19 flyby of Mars, Thursday, Oct. 9, 2014 at NASA Headquarters in Washington.  Photo Credit: (NASA/Joel Kowsky)
Mars Comet Encounter Briefing
Dwayne Brown, NASA public affairs officer, moderates a media briefing where panelists outlined how space and Earth-based assets will be used to image and study comet Siding Spring during its Sunday, Oct. 19 flyby of Mars, Thursday, Oct. 9, 2014 at NASA Headquarters in Washington.  Photo Credit: (NASA/Joel Kowsky)
Mars Comet Encounter Briefing
Padma Yanamandra-Fisher, senior research scientist, Space Science Institute, Rancho Cucamonga Branch, California, right, gives remarks during a media briefing where she and other panelists outlined how space and Earth-based assets will be used to image and study comet Siding Spring during its Sunday, Oct. 19 flyby of Mars, Thursday, Oct. 9, 2014 at NASA Headquarters in Washington.  Photo Credit: (NASA/Joel Kowsky)
Mars Comet Encounter Briefing
The Compact Reconnaissance Imaging Spectrometer for Mars CRISM aboard NASA Mars Reconnaissance Orbiter obtained this spectrum for comet C/2013 A1 Siding Spring during the comet close approach to Mars.
Mars-Orbiting Spectrometer Shows Dusty Comet Spectrum
These images were taken of comet C/2013 A1 Siding Spring by NASA Mars Reconnaissance Orbiter on Oct. 19, 2014, during the comet close flyby of Mars and the spacecraft.
First Resolved Image of a Long-Period Comet Nucleus
Is it a bird, or a plane? No, it comet Siding Spring streaking across the sky, as seen by NASA Wide-field Infrared Survey Explorer, or WISE. An animation is available at the Photojournal.
Ablaze with Infrared Light
Panelists, from left, Jim Green, director, Planetary Science Division, NASA Headquarters, Washington, Carey Lisse, senior astrophysicist, Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, Kelly Fast, program scientist, Planetary Science Division, NASA Headquarters, Washington, and Padma Yanamandra-Fisher, senior research scientist, Space Science Institute, Rancho Cucamonga Branch, California, are seen during a media briefing where they outlined how space and Earth-based assets will be used to image and study comet Siding Spring during its Sunday, Oct. 19 flyby of Mars, Thursday, Oct. 9, 2014 at NASA Headquarters in Washington. (Photo credit: NASA/Joel Kowsky)
Mars Comet Encounter Briefing
Panelists, from left, Jim Green, director, Planetary Science Division, NASA Headquarters, Washington, Carey Lisse, senior astrophysicist, Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, Kelly Fast, program scientist, Planetary Science Division, NASA Headquarters, Washington, and Padma Yanamandra-Fisher, senior research scientist, Space Science Institute, Rancho Cucamonga Branch, California, are seen during a media briefing where they outlined how space and Earth-based assets will be used to image and study comet Siding Spring during its Sunday, Oct. 19 flyby of Mars, Thursday, Oct. 9, 2014 at NASA Headquarters in Washington. (Photo credit: NASA/Joel Kowsky)
Mars Comet Encounter Briefing
Jim Green, director, Planetary Science Division, NASA Headquarters, Washington, left,  is seen with fellow panelists Carey Lisse, senior astrophysicist, Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, Kelly Fast, program scientist, Planetary Science Division, NASA Headquarters, Washington, and Padma Yanamandra-Fisher, senior research scientist, Space Science Institute, Rancho Cucamonga Branch, California during a media briefing where they outlined how space and Earth-based assets will be used to image and study comet Siding Spring during its Sunday, Oct. 19 flyby of Mars, Thursday, Oct. 9, 2014 at NASA Headquarters in Washington.  Photo Credit: (NASA/Joel Kowsky)
Mars Comet Encounter Briefing
Panelists, from left, Jim Green, director, Planetary Science Division, NASA Headquarters, Washington, Carey Lisse, senior astrophysicist, Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, Kelly Fast, program scientist, Planetary Science Division, NASA Headquarters, Washington, and Padma Yanamandra-Fisher, senior research scientist, Space Science Institute, Rancho Cucamonga Branch, California, are seen during a media briefing where they outlined how space and Earth-based assets will be used to image and study comet Siding Spring during its Sunday, Oct. 19 flyby of Mars, Thursday, Oct. 9, 2014 at NASA Headquarters in Washington. (Photo credit: NASA/Joel Kowsky)
Mars Comet Encounter Briefing
Dwayne Brown, NASA public affairs officer, left, moderates a media briefing where panelist, seated from left, Jim Green, director, Planetary Science Division, NASA Headquarters, Washington, Carey Lisse, senior astrophysicist, Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, Kelly Fast, program scientist, Planetary Science Division, NASA Headquarters, Washington, and Padma Yanamandra-Fisher, senior research scientist, Space Science Institute, Rancho Cucamonga Branch, California, outlined how space and Earth-based assets will be used to image and study comet Siding Spring during its Sunday, Oct. 19 flyby of Mars, Thursday, Oct. 9, 2014 at NASA Headquarters in Washington. (Photo credit: NASA/Joel Kowsky)
Mars Comet Encounter Briefing
Researchers used the Pancam on NASA Mars Exploration Rover Opportunity to capture this view of comet C/2013 A1 Siding Spring as it flew near Mars on Oct. 19, 2014.
Mars Rover Opportunity View of Passing Comet
These two infrared images of comet C/2013 A1 Siding Spring were taken by the Compact Reconnaissance Imaging Spectrometer for Mars CRISM aboard NASA Mars Reconnaissance Orbiter on Oct. 19, 2014.
Images From Mars-Orbiting Spectrometer Show Comet Coma
Researchers used the Pancam on NASA Mars Exploration Rover Opportunity to capture this view of comet C/2013 A1 Siding Spring as it flew near Mars on Oct. 19, 2014.
Mars Rover Opportunity View of Passing Comet Short Exposure
Five images of comet Siding Spring taken within a 35-minute period as it passed near Mars on Oct. 19, 2014, provide information about the size of the comet nucleus. The images were acquired by the HiRISE camera on NASA Mars Reconnaissance Orbiter.
Mars Orbiter Sizes Up Passing Comet
This frame from a movie sequence of images from NASA Mars Reconnaissance Orbiter MRO shows comet C/2013 A1 Siding Spring before and after its close pass by Mars in October 2014. False color enhances subtle variations in brightness in the comet coma.
Mars-Flyby Comet in False Color
Comet Siding Spring appears to streak across the sky like a superhero in this new infrared image from NASA Wide-field Infrared Survey Explorer. The comet, also known as C/2007 Q3, was discovered in 2007 by observers in Australia.
Visitor from Deep Space
This graph shows changes in apparent brightness of comet C/2013 A1 Siding Spring as it approached and receded from Mars, as seen by the HiRISE camera on NASA Mars Reconnaissance Orbiter. The pattern suggests the comet rotates once every eight hours.
Brightness Rhythm of Mars Flyby Comet Is Clue to Rotation Rate
This two-image blink shows a comparison of two exposure times in images from the panoramic camera Pancam on NASA Mars Exploration Rover Opportunity showing comet C/2013 A1 Siding Spring as it flew near Mars on Oct. 19, 2014.
Mars Rover Opportunity View of Comet Blink of Two Exposures
These eight graphs present data from the Neutral Gas and Ion Mass Spectrometer on NASA MAVEN orbiter identifying ions of different metals added to the Martian atmosphere shortly after comet C/2013 A1 Siding Spring sped close to Mars.
Ions of Eight Metals from Comet Dust Detected in Mars Atmosphere
This frame from an animated artist rendering begins with NASA Mars Reconnaissance Orbiter spacecraft above Mars. The movie then transitions to a sequence of HiRISE images of the comet taken as it flew past Mars.
Mars Orbiter Observes Comet Siding Spring Animation
Photo by Peter McGregor  Comet Shoemaker-Levy 9 impacting Jupiter; impact of Fragment G of Comet Shoemaker-Levy on Jupiter. The fireball is seen 12 minutes after impact at 2.34 microns. The impact A site is seen on the oposite limb of the planet. Image at 2.34 microns with CASPIR by Peter McGregor ANU 2.3m telescope at Siding Spring. (JPL Ref; P-44419)
ARC-1994-AC94-0353-3
NASA image release October 5, 2010  Hubble Space Telescope observations of comet 103P/Hartley 2, taken on September 25, are helping in the planning for a November 4 flyby of the comet by NASA's Deep Impact eXtended Investigation (DIXI) spacecraft.  Analysis of the new Hubble data shows that the nucleus has a diameter of approximately 0.93 miles (1.5 km), which is consistent with previous estimates.  The comet is in a highly active state, as it approaches the Sun. The Hubble data show that the coma is remarkably uniform, with no evidence for the types of outgassing jets seen from most &quot;Jupiter Family&quot; comets, of which Hartley 2 is a member.  Jets can be produced when the dust emanates from a few specific icy regions, while most of the surface is covered with relatively inert, meteoritic-like material. In stark contrast, the activity from Hartley 2's nucleus appears to be more uniformly distributed over its entire surface, perhaps indicating a relatively &quot;young&quot; surface that hasn't yet been crusted over.  Hubble's spectrographs - the Cosmic Origins Spectrograph (COS) and the Space Telescope Imaging Spectrograph (STIS) -- are expected to provide unique information about the comet's chemical composition that might not be obtainable any other way, including measurements by DIXI. The Hubble team is specifically searching for emissions from carbon monoxide (CO) and diatomic sulfur (S2). These molecules have been seen in other comets but have not yet been detected in 103P/Hartley 2.  103P/Hartley has an orbital period of 6.46 years. It was discovered by Malcolm Hartley in 1986 at the Schmidt Telescope Unit in Siding Spring, Australia. The comet will pass within 11 million miles of Earth (about 45 times the distance to the Moon) on October 20. During that time the comet may be visible to the naked eye as a 5th magnitude &quot;fuzzy star&quot; in the constellation Auriga.  Credit: NASA, ESA, and H. Weaver (The Johns Hopkins University/Applied Physics Lab)  The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI) conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.  <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>Join us on <a href="http://www.facebook.com/pages/Greenbelt-MD/NASA-Goddard/395013845897?ref=tsd" rel="nofollow">Facebook</a></b>
Hubble Probes Comet 103P/Hartley 2 in Preparation for DIXI flyby
This is a radar image of the southwest portion of the buried Chicxulub impact crater in the Yucatan Peninsula, Mexico.  The radar image was acquired on orbit 81 of space shuttle Endeavour on April 14, 1994 by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR). The image is centered at 20 degrees north latitude and 90 degrees west longitude.  Scientists believe the crater was formed by an asteroid or comet which slammed into the Earth more than 65 million years ago. It is this impact crater that has been linked to a major biological catastrophe where more than 50 percent of the Earth's species, including the dinosaurs, became extinct. The 180-to 300-kilometer-diameter (110- to 180-mile) crater is buried by 300 to 1,000 meters (1,000 to 3,000 feet) of limestone. The exact size of the crater is currently being debated by scientists.  This is a total power radar image with L-band in red, C-band in green, and the difference between C-band L-band in blue. The 10-kilometer-wide (6-mile) band of yellow and pink with blue patches along the top left (northwestern side) of the image is a mangrove swamp. The blue patches are islands of tropical forests created by freshwater springs that emerge through fractures in the limestone bedrock and are most abundant in the vicinity of the buried crater rim. The fracture patterns and wetland hydrology in this region are controlled by the structure of the buried crater. Scientists are using the SIR-C/X-SAR imagery to study wetland ecology and help determine the exact size of the impact crater.  http://photojournal.jpl.nasa.gov/catalog/PIA01723
Space Radar Image of the Yucatan Impact Crater Site