This color image draped onto digital topography shows McLaughlin Crater in a 3D perspective, looking toward the east. Light-toned deposits on the crater floor contain alteration minerals that are overlayed by debris flows from Keren Crater, present on the south rim. McLaughin Crater once contained a lake that was likely fed by groundwater.
This image combining orbital imagery with 3-D modeling shows flows that appear in spring and summer on a slope inside Mars' Newton crater.
These slopes on Mars, as photographed by the High Resolution Imaging Science Experiment (HiRise) on the Mars Reconnaissance Orbiter, may have been carved by saltwater that could run down the Martian surface each spring.
This map of Mars shows relative locations of three types of findings related to salt or frozen water, plus a new type of finding that may be related to both salt and water. Blue boxes are caches of water ice; white boxes are fresh craters that exposed water ice; red boxes are salt deposits that may be from salt water evaporation.
The slopes on Mars that might host liquid runs of saltwater are seen here with a synthetic Mars-like sky in the background.
This composite image shows odd lines on slopes of Mars' Horowitz Crater, which scientists say suggest the presence of liquid salt water. These images show the central structure of Horowitz Crater, including central peaks and pits. The arrows mark locations of the odd slope features.
These slopes carved in Horowitz crater on Mars suggest the Red Planet might current host liquid water. Colors have been strongly enhanced to show the subtle differences, including light orange streaks (black arrows) in the upper right that may mark faded lines.
An impact crater in Mars' Newton basin shows lines that appear to have been carved by salt water. Four side panels show these lines in the late summer on Mars (B), then faded by the next very early spring (C), then gradually darkening and reforming in the spring (D) and summer (E).
Crater edge in Terra Sirenum has been imaged by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. Gully watching thanks to repeat sweeps over the same landscape by orbiting spacecraft could catch gullies in action, if they are active today.
Pockets of water ice on the southern pole of Mars, such as these, have been stopped from their once-routine migration by a cap of dry ice, or frozen carbon dioxide. Planetary scientists think the migrations was fueled by an eccentric wobble in Mars'tilt.
The Shallow Radar instrument on NASA's Mars Reconnaissance Orbiter has detected widespread deposits of glacial ice in the mid-latitudes of Mars. This map of a region known as Deuteronilus Mensae, in the northern hemisphere, shows locations of the detected ice deposits in blue.
An annotated look at the huge McLaughlin Crater on Mars, showing locations of minerals and clays created by water in the ancient past. The region may have once been a groundwater lake billions of years ago. Image released Jan. 20, 2013.
Stages in the seasonal disappearance of surface ice from the ground around the Phoenix Mars Lander are visible in these images taken on Feb. 8, 2010, (left) and Feb. 25, 2010, during springtime on northern Mars, by NASA's Mars Reconnaissance Orbiter.
Tongue-shaped features called lobate flows were seen on the wall of a 37-mile (60-km) diameter crater on the Martian surface. (Image taken with the Mars Oddysey THEMIS VIS camera.)
This radar map shows the thickness of the south polar layered deposits of Mars (purple represents the thinnest areas and red the thickest). The dark circle is the area poleward of 87 degrees south latitude, where MARSIS can’t collect radar data.
In this perspective view looking at the inside rim of Lyot Crater on Mars, a broad lobate debris apron (left) (thought to be a debris-covered glacier) is found amongst water-carved channels. The authors argue that these ice-rich units underwent melting in the relatively high-pressure environment provided by Lyot Crater, the deepest point in the northern hemisphere of Mars.
The floor and banks of a Mars gully on the northwest wall of a crater in Terra Sirenium changed between December 2001 and April 2005 due to a distinct light-toned material that flowed down the slope and formed a deposit (top). The same change occurred in a crater in the Centauri Montes region (bottom).
Melting glaciers spawned rivers on Mars as recently as several hundred million years ago. This image shows a river that sprang from a past glacier from an unnamed crater in Mars’ middle latitudes. Full Story.
At the center of this view of an area of mid-latitude northern Mars, a fresh crater about 6 meters (20 feet) in diameter holds an exposure of bright material, blue in this false-color image.
The ancient oceans or seas thought to have covered ancient Mars 3 billion years ago, as shown in this artist's rendition based on actual topography of Mars from NASA Mars Orbiter Laser Altimeter, may have sprung up through surface cracks.
A view of Mars as it might have appeared more than 2 billion years ago, with an ocean filling the lowland basin that now occupies the north polar region.
Chains of crater marks on Mars such as these could have been made by icebergs rolling across ancient Martian ocean floors, researchers suggest.
This is a global map depicting the dissection density of valley networks on Mars, in relation to the hypothesized northern ocean. Two candidate sea levels are shown: contact 1 with mean elevation at -1,680 meters and contact 2 with mean elevation of -3,760 meters.
Boulders over northern lowland terrains on Mars.
The picture shows a topographic map of a crater in the Xanthe highlands, which held a lake 3.8 to 4 billion years ago. Sediments were deposited in the lake, forming a distinctly shaped delta. The lake was fed by a river that flowed through the Nanedi valley and into the crater from the south.
Dense clusters of crack-like structures called deformation bands form the linear ridges in this Mars image from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter.
Cracks caused by the contraction of sulfate are evident in this image of the surface of Mars' Meridiani Planum site by NASA's Opportunity Rover.
This view of layered rocks on the floor of McLaughlin Crater shows sedimentary rocks that contain spectroscopic evidence for minerals formed through interaction with water. The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter recorded the image. Image released Jan. 20, 2013.