Wheel tracks from NASA's Mars rover Opportunity descending and departing the "Cape Tribulation" segment of Endeavour Crater's rim are visible in this April 21, 2017, view from the rover's Pancam. This version is presented in enhanced color to make differences in surface materials more visible.
Wheel tracks from NASA's Mars rover Opportunity descending and departing the "Cape Tribulation" segment of Endeavour Crater's rim are visible in this April 21, 2017, view from the rover's Panoramic Camera (Pancam). The rover looked back northward during its trek south to "Perseverance Valley."
This graphic shows the route that NASA's Mars Exploration Rover Opportunity drove in its final approach to "Perseverance Valley" on the western rim of Endeavour Crater during spring 2017.
"Perseverance Valley" lies just on the other side of the dip in the crater rim visible in this view from the Navigation Camera (Navcam) on NASA's long-lived Mars Exploration Rover Opportunity, which arrived at this destination in early May 2017 in preparation for driving down the valley.
This view from the Mast Camera (Mastcam) on NASA's Curiosity Mars rover shows two scales of ripples, plus other textures, in an area where the mission examined a linear-shaped dune in the Bagnold dune field on lower Mount Sharp in March and April 2017.
This 360-degree scene from the Mastcam on NASA's Curiosity Mars rover includes part of a linear-shaped dune the rover examined in early 2017 for comparison with what it found previously at crescent-shaped dunes. The view shows the dark, rippled surface of the active dune, near sedimentary bedrock.
The bright landing platform left behind by NASA's Mars Exploration Rover Opportunity in 2004 is visible inside Eagle Crater, where "Opportunity Lander" is indicated in this annotated, April 8, 2017, image from NASA's Mars Reconnaissance Orbiter.
The bright landing platform left behind by NASA's Mars Exploration Rover Opportunity in 2004 is visible inside Eagle Crater, at upper right in this April 8, 2017, observation by NASA's Mars Reconnaissance Orbiter.
The JPL team that recently tested life-detecting devices in Chile's Atacama Desert, from left to right: Peter Willis, Jessica Creamer, Fernanda Mora, Eric Tavares Da Costa and Florian Kehl.
This image shows segments of the western rim of Mars' Endeavour Crater. NASA's Mars rover Opportunity has explored parts of the rim since 2011. The view covers an area about 9 miles wide. It was taken by the Context Camera on NASA's Mars Reconnaissance Orbiter.
A grooved ridge called "Rocheport" on the rim of Mars' Endeavour Crater spans this stereo scene from NASA's Mars rover Opportunity. The view combines images from left eye and right eye of the rover's Pancam to appear three-dimensional when seen through blue-red glasses with the red lens on the left.
A grooved ridge called "Rocheport" on the rim of Mars' Endeavour Crater spans this scene from the Pancam on NASA's Mars rover Opportunity. This version of the scene is presented in enhanced color to make differences in surface materials more easily visible.
A grooved ridge called "Rocheport" on the rim of Mars' Endeavour Crater spans this scene from the Pancam on NASA's Mars rover Opportunity. The view extends from south-southeast on the left to north on the right. The site is near the southern end of an Endeavour rim segment called "Cape Tribulation."
NASA's MAVEN spacecraft measured light and heavy isotopes of argon in the Martian atmosphere, allowing scientists to determine that the majority of the planet's air was lost to space.
The 2017 National Air and Space Museum Trophy for Lifetime Achievement was handed to Peter Theisinger, left, by Gen. J.R. "Jack" Dailey, the museum's director, on March 29. At NASA's Jet Propulsion Laboratory, Theisinger worked on missions to six planets and led projects that put three rovers on Mars.
This map shows the footprints of images taken by the HiRISE camera on NASA's Mars Reconnaissance Orbiter as part of advance analysis of the area where NASA's InSight mission will land in 2018. The final planned image of the set will fill in the yellow-outlined rectangle on March 30, 2017.
In early 2017, after more than a decade of observing Mars, the Context Camera on NASA's Mars Reconnaissance Orbiter (MRO) surpassed 99 percent coverage of the entire planet. This mosaic shows that global coverage. No other camera has ever imaged so much of Mars in such high resolution.
The Context Camera on NASA's Mars Reconnaissance Orbiter has been taking images of Mars since 2006. This animation shows, at one frame per month, how these observations have accumulated to cover more than 99 percent of Mars. No other camera has ever shown so much of Mars in such high resolution.
Two of the raised treads, called grousers, on the left middle wheel of NASA's Curiosity Mars rover broke during the first quarter of 2017, including the one seen partially detached at the top of the wheel in this image from the Mars Hand Lens Imager (MAHLI) camera on the rover's arm.
This false-color scene from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity documents movement of dust as a regional dust storm approached the rover's location on Feb. 24, 2017, during the 4,653rd Martian day, or sol, of the rover's work on Mars.
This false-color scene from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity documents movement of dust as a regional dust storm approached the rover's location on Feb. 24, 2017, during the 4,653rd Martian day, or sol, of the rover's work on Mars.
This movie clip shows a global map of Mars with atmospheric changes from Feb. 18, 2017, through March 6, 2017, a period when two regional-scale dust storms appeared. It combines hundreds of images from the Mars Color Imager (MARCI) camera on NASA's Mars Reconnaissance Orbiter.
This sequence of images shows a dust-carrying whirlwind, called a dust devil, on lower Mount Sharp inside Gale Crater, as viewed by NASA's Curiosity Mars Rover during the summer afternoon of the rover's 1,613rd Martian day, or sol (Feb. 18, 2017).
Dust devils dance in the distance in this sequence of images taken by the Navigation Camera on NASA's Curiosity Mars rover on Feb. 12, 2017, during the afternoon of the rover's 1,607th Martian day, or sol.
Beyond a dark sand dune closer to the rover, a Martian dust devil passes in front of the horizon in this sequence of images from NASA's Curiosity Mars rover. The rover's Navigation Camera made this series of observations on Feb. 4, 2017, during the local afternoon in Mars' Gale Crater.
This sequence of images shows a dust-carrying whirlwind, called a dust devil, scooting across ground inside Gale Crater, as observed on the local summer afternoon of NASA's Curiosity Mars Rover's 1,597th Martian day, or sol (Feb. 1, 2017). Timing is accelerated in this animation.
This map shows the two locations of a research campaign by NASA's Curiosity Mars rover mission to investigate active sand dunes on Mars. In late 2015, Curiosity reached crescent-shaped dunes, called barchans. In February 2017, the rover reached a location where the dunes are linear in shape.
The left side of this 360-degree panorama from NASA's Curiosity Mars rover shows the long rows of ripples on a linear shaped dune in the Bagnold Dune Field on the northwestern flank of Mount Sharp. The rover's Navigation Camera recorded the component images of this mosaic on Feb. 5, 2017.
This pair of images shows effects of one Martian day of wind blowing sand underneath NASA's Curiosity Mars rover on a non-driving day for the rover. Each image was taken just after sundown by the rover's Mars Descent Imager (MARDI). The area of ground shown spans about 3 feet left-to-right.
NASA's Mars Reconnaissance Orbiter has been observing Mars since 2006, enabling it to document many types of changes, such as the way winds alter the appearance of this recent impact site. The orbiter's HiRISE camera took the four images used in this animated sequence in 2007, 2008, 2010 and 2012.
Mono Lake, California, with salt pillars known as "tufas" visible. JPL scientists tested new methods for detecting chemical signatures of life in the salty waters here, believing them to be analogs for water on Mars or ocean worlds like Europa.
This photograph from Shiprock in northwestern New Mexico shows a ridge roughly 30 feet (about 10 meters) tall that formed from lava filling an underground fracture then resisting erosion better than the material around it did.
This stereo view shows an area on Mars where narrow rock ridges intersect at angles forming corners of polygons. It combines two observations from the HiRISE camera on NASA's Mars Reconnaissance Orbiter and appears three-dimensional when viewed through red-blue glasses with the red lens on the left.
This view from the HiRISE camera on NASA's Mars Reconnaissance Orbiter shows part of an area on Mars where narrow rock ridges, some as tall as a 16-story building, intersect at angles forming corners of polygons.
Infographic with information about the Mars Exploration Rovers, Spirit and Opportunity. Opportunity will celebrate 13 years on Mars on Jan. 24. The rover is currently exploring the rim of Endeavour Crater.
A grid of small polygons on the Martian rock surface near the right edge of this view may have originated as cracks in drying mud more than 3 billion years ago. Multiple Dec. 20, 2016, images from the Mastcam on NASA's Curiosity Mars rover were combined for this view of a rock called "Squid Cove."
This view of a Martian rock slab called "Old Soaker," which has a network of cracks that may have originated in drying mud, comes from the Mast Camera (Mastcam) on NASA's Curiosity Mars rover. It was taken on Dec. 20, 2016. The slab is about 4 feet long.
The network of cracks in this Martian rock slab called "Old Soaker" may have formed from the drying of a mud layer more than 3 billion years ago. The view spans about 3 feet (90 centimeters) left-to-right and combines three images taken by the MAHLI camera on the arm of NASA's Curiosity Mars rover.
Here is a view of Earth and its moon, as seen from Mars. It combines two images acquired on Nov. 20, 2016, by the HiRISE camera on NASA's Mars Reconnaissance Orbiter, with brightness adjusted separately for Earth and the moon to show details on both bodies. Relative sizes and distance are correct.
These five images from the HiRISE camera on NASA's Mars Reconnaissance Orbiter show different Martian features of progressively greater size and complexity, all thought to result from thawing of seasonal carbon dioxide ice that covers large areas near Mars' south pole during winter.
This sequence of three HiRISE images from NASA's Mars Reconnaissance Orbiter shows the growth of a branching network of troughs carved by thawing carbon dioxide over the span of three Martian years. This process may also form larger radially patterned channel features known as Martian "spiders."
This pair of drawings depicts the same location at Gale Crater on at two points in time: now and billions of years ago. Water moving beneath the ground, as well as water above the surface in ancient rivers and lakes, provided favorable conditions for microbial life, if Mars has ever hosted life.
The foreground of this scene from the Mastcam on NASA's Curiosity Mars rover shows purple-hued rocks near the rover's late-2016 location. The middle distance includes future destinations for the rover. Variations in color of the rocks hint at the diversity of their composition on lower Mount Sharp.
This graphic maps locations of the sites where NASA's Curiosity Mars rover collected its first 19 rock or soil samples for laboratory analysis inside the vehicle. It also presents images of the drilled holes where 15 rock-powder samples were acquired, most recently at "Sebina," on Oct. 20, 2016.
This graphic portrays two hypotheses about how the element boron ended up in calcium sulfate veins found within mudstone layers of Mars' lower Mount Sharp.
Examination of a calcium sulfate vein called "Diyogha" by the ChemCam instrument on NASA's Curiosity Mars rover found boron, sodium and chlorine. An image from the rover's Mastcam, at left, provides context for the magnified image and composition information from ChemCam, at right.
The highest concentration of boron measured on Mars, as of late 2016, is in this mineral vein examined with the ChemCam instrument on NASA's Curiosity rover on Aug, 25, 2016. Orange bars indicate boron content at points in the calcium sulfate vein. The context image is from Curiosity's Mastcam.
This map shows the route driven by NASA's Curiosity Mars rover (blue line) and locations where the rover's ChemCam instrument detected the element boron (dots, colored by abundance of boron according to the key at right). The inset is a blowup of the most recent portion of the traverse.
This graphic shows proportions of minerals identified by the Curiosity Mars rover's CheMin instrument in mudstone outcrops at "Yellowknife Bay" in 2013 and at "Murray Buttes" in 2016. For example, the rover found more hematite and less magnetite at Murray Buttes, compared with Yellowknife Bay.
This graphic illustrates how dimensions of clay minerals' crystal structure are affected by which ions are present in the mineral. The CheMin instrument on NASA's Curiosity Mars rover identified different clay minerals this way at two sites in Gale Crater: "Murray Buttes" and "Yellowknife Bay."
Data graphed here from the Chemistry and Camera (CheMin) instrument on NASA's Mars Curiosity rover show a difference between clay minerals in powder drilled from mudstone outcrops at two locations in Mars' Gale Crater: "Yellowknife Bay" and "Murray Buttes."
This series of pie charts shows similarities and differences in the mineral composition of mudstone at 10 sites where NASA's Curiosity Mars rover collected rock-powder samples and analyzed them with the rover's Chemistry and Mineralogy (CheMin) instrument.
This graphic depicts aspects of the driving distance, elevation, geological units and time intervals of NASA's Curiosity Mars rover mission, as of late 2016. The vertical dimension is exaggerated 14-fold compared with the horizontal dimension, for presentation-screen proportions.
This map shows the route driven by NASA's Curiosity Mars rover from the location where it landed in August 2012 to its location in December 2016, which is in the upper half of a geological unit called the Murray Formation, on lower Mount Sharp.
This May 29, 2016, image of a target called "Private Joseph Field" combines images from the microscopic imager on NASA's Mars Exploration Rover Opportunity with enhanced color information from the rover's panoramic camera. The target is on the western rim of Mars' Endeavour Crater.
This rock, dubbed "Gasconade," was investigated by NASA's Mars Exploration Rover Opportunity while the rover was perched on "Spirit Mound" at the western edge of Mars' Endeavour Crater. Four Oct. 2, 2016, frames from Opportunity's microscopic imager are joined in this mosaic view.
This Dec. 2, 2016, view from the Navigation Camera (Navcam) on the mast of NASA's Curiosity Mars Rover shows rocky ground within view while the rover was working at an intended drilling site called "Precipice" on lower Mount Sharp.
A NASA radio on Europe's Trace Gas Orbiter, which reached Mars in October 2016, has succeeded in its first test of receiving data from NASA Mars rovers, both Opportunity and Curiosity. This graphic depicts the geometry of the relay from Opportunity to the orbiter, which then sent the data to Earth.
Diagonal striping on this map of a portion of Mars' Utopia Planitia region indicates the area where a large subsurface deposit rich in water ice was assessed using the Shallow Radar (SHARAD) instrument on NASA's Mars Reconnaissance Orbiter. The deposit holds about as much water as Lake Superior.
These two images show Shallow Radar (SHARAD) instrument data from two tracks in a part of Mars' Utopia Planitia region where the orbiting, ground-penetrating radar on NASA's Mars Reconnaissance Orbiter detected subsurface deposits rich in water ice.
This vertically exaggerated view shows scalloped depressions in a part of Mars where such textures prompted researchers to check for buried ice, using ground-penetrating radar aboard NASA's Mars Reconnaissance Orbiter. They found about as much frozen water as the volume of Lake Superior.
These views of sites where hardware from Europe's Schiaparelli test lander hit Mars on Oct. 19, 2016, combine two HiRISE camera orbital views from different angles, as a stereo pair for viewing with red-blue glasses. Top: lander; lower left: parachute and back shell; lower right: heat shield.
On Nov. 1, 2016, the HiRISE camera on NASA's Mars Reconnaissance Orbiter observed the impact site of Europe's Schiaparelli test lander, gaining the first color view of the site since the lander's Oct. 19 arrival. These cutouts cover locations where three parts of the spacecraft reached the ground.
The dark, smooth-surfaced rock at the center of this Oct. 30, 2016, image from the Mast Camera (Mastcam) on NASA's Curiosity Mars rover was examined with laser pulses and confirmed to be an iron-nickel meteorite. It is about the size of a golf ball.
The dark, golf-ball-size object in this composite, colorized view from the ChemCam instrument on NASA's Curiosity Mars rover is a nickel-iron meteorite, as confirmed by analysis using laser pulses from ChemCam on Oct. 30, 2016. The grid of bright spots on the rock resulted from the laser pulses.
This Oct. 25, 2016, image from the HiRISE camera on NASA's Mars Reconnaissance Orbiter shows the area where the Europe's Schiaparelli test lander struck Mars, with magnified insets of three sites where spacecraft components hit the ground. It adds detail not seen in earlier imaging of the site.
This comparison of before-and-after images shows two spots that likely appeared in connection with the Oct. 19, 2016, Mars arrival of the European Space Agency's Schiaparelli test lander. The images are from the Context Camera on NASA's Mars Reconnaissance Orbiter.
This image shows spidery channels eroded into Martian ground. It is a Sept. 12, 2016, example from HiRISE camera high-resolution observations of more than 20 places that were chosen in 2016 on the basis of about 10,000 volunteers' examination of Context Camera lower-resolution views of larger areas.
This artist's concept from the European Space Agency depicts the Trace Gas Orbiter and its entry, descent and landing demonstrator module, Schiaparelli, approaching Mars. The separation occurred on Oct. 16, 2016. The orbiter and the lander are components of the ExoMars 2016 mission of ESA and Roscosmos.
This image shows atomic hydrogen scattering sunlight in the upper atmosphere of Mars, as seen by the Imaging Ultraviolet Spectrograph on NASA's Mars Atmosphere and Volatile Evolution mission.
This map show a portion of Endeavour Crater's western rim that includes
the "Marathon Valley" area investigated intensively by NASA's Mars Exploration Rover Opportunity in 2015 and 2016, and a fluid-carved gully that is a destination to the south for the mission.
This stereo scene from NASA's Mars Exploration Rover Opportunity shows "Spirit Mound" overlooking the floor of Endeavour Crater. The view appears three-dimensional when seen through blue-red glasses with the red lens on the left.
This Sept. 21, 2016, scene from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity shows "Spirit Mound" overlooking the floor of Endeavour Crater. The mound stands near the eastern end of "Bitterroot Valley" on the western rim of the crater, and this view faces eastward.
This Sept. 21, 2016, scene from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity shows "Spirit Mound" overlooking the floor of Endeavour Crater. The mound stands near the eastern end of "Bitterroot Valley" on the western rim of the crater, and this view faces eastward.
This scene from NASA's Mars rover Opportunity shows "Wharton Ridge," on the western rim of Endeavour Crater. The ridge's name honors the memory of astrobiologist Robert A. Wharton (1951-2012). The scene is presented in enhanced color to make differences in surface materials more easily visible.
This scene from NASA's Mars rover Opportunity shows "Wharton Ridge," which forms part of the southern wall of "Marathon Valley" on the rim of Endeavour Crater. The ridge's name honors the memory of astrobiologist Robert A. Wharton (1951-2012). The scene is presented in approximately true color.
This graphic indicates a similarity between 2016 (dark blue line) and five past years in which Mars has experienced global dust storms (orange lines and band), compared to years with no global dust storm (blue-green lines and band). The horizontal scale is time-of-year on Mars
Two 2001 images from the Mars Orbiter Camera on NASA's Mars Global Surveyor orbiter show a dramatic change in the planet's appearance when haze raised by dust-storm activity in the south became globally distributed. The images were taken about a month apart.
A prototype of the Lander Vision System for NASA's Mars 2020 mission was tested in this Dec. 9, 2014, flight of a Masten Space Systems "Xombie" vehicle at Mojave Air and Space Port in California.
MAVEN's Imaging UltraViolet Spectrograph obtained this image of Mars on July 13, 2016, when the planet appeared nearly full when viewed from the highest altitudes in the MAVEN orbit.
This September 2016 self-portrait of NASA's Curiosity Mars rover shows the vehicle at the "Quela" drilling location in the scenic "Murray Buttes" area on lower Mount Sharp. The panorama was stitched together from multiple images taken by the MAHLI camera at the end of the rover's arm.
This 360-degree panorama was acquired on Sept. 4, 2016, by the Mast Camera on NASA's Curiosity Mars rover while the rover was in a scenic area called "Murray Buttes" on lower Mount Sharp. The flat-topped mesa near the center of the scene rises to about 39 feet above the surrounding plain.
This map shows the route driven by NASA's Curiosity Mars rover from the location where it landed in August 2012 to its location in September 2016 at "Murray Buttes," and the path planned for reaching destinations at "Hematite Unit" and "Clay Unit" on lower Mount Sharp.
This graphic maps locations of the sites where NASA's Curiosity Mars rover collected its first 18 rock or soil samples for laboratory analysis inside the vehicle. It also presents images of the drilled holes where 14 rock-powder samples were acquired, most recently at "Quela," on Sept. 18, 2016.
The top of the butte in this Sept. 1, 2016, scene from the Mast Camera (Mastcam) on NASA's Curiosity Mars rover stands about 16 feet above the rover and about 82 feet east-southeast of the rover. The site is in the "Murray Buttes" area of lower Mount Sharp, and this particular butte is called "M9a."
The mesa in the center of this scene from the "Murray Buttes" area on Mars is longer than a football field. The panorama combines images taken by the Mastcam on NASA's Curiosity Mars rover on Aug. 22 and Aug. 23, 2016.
The two prominent mesas in this Aug. 18, 2016, view of Mars' "Murray Buttes" region from the Curiosity Mars rover's Mastcam are about 260 feet (about 80 meters) apart. The one on the right is about 33 feet high, and its top is about 270 feet from the rover's position when the images were taken.
Processes in Mars' surface material can explain why particular xenon (Xe) and krypton (Kr) isotopes are more abundant in the Martian atmosphere than expected, as measured by NASA's Curiosity rover. Cosmic rays striking barium (Ba) or bromine (Br) atoms can alter isotopic ratios of xenon and krypton.
Apollo 11 astronaut Buzz Aldrin, right, and Erisa Hines of NASA's Jet Propulsion Laboratory in Pasadena, California, try out the Microsoft Hololens mixed reality headset during a preview of "Destination: Mars" at Kennedy Space Center visitor complex in Florida.
