Artist concept of Glaciers on Mars

This image from NASA's Mars Reconnaissance Orbiter shows many new ice blocks compared to earlier images in 2006. One of the most actively changing areas on Mars are the steep edges of the North Pol...

Dark, seasonal flows emanate from bedrock exposures at Palikir Crater on Mars in this image from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter.

This 3D, or stereo anaglyph, view shows the parachute and back shell that helped guide NASA's Curiosity to the surface of Mars.

Image of Hesperia Planum from the HiRISE camera on Mars Reconnaissance Orbiter.

NASA's Curiosity Mars rover can be seen at the "Pahrump Hills" area of Gale Crater in this view from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orb...

The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter snapped this series of false-color pictures of sand dunes in the north polar region of Mars

This Southern autumn image captures a view of frosty dunes. The sunlight is shining on the dunes from the upper right.

This movie sequence of images from NASA's 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 ...

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 2015, at examples of the Bagnold Dunes.

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 reachi...

This proposed future Mars landing site in Acidalia Planitia targets densely occurring mounds thought to be mud volcanoes.

This image from NASA's Mars Reconnaissance Orbiter shows an impact crater that triggered a slope streak. When a meteoroid hit the surface and exploded to make the crater, it destabilized the slope ...

Animation of a skinny "dust devil" on the dust-covered Amazonis Planitia region of northern Mars. (No audio)

This back and forth comparison shows changes that occurred in a gully on a south-facing slope in middle southern latitudes of Mars.

This image from the NASA Mars Reconnaissance Orbiter shows an impact scar on Mars made by pieces of the NASA Mars Science Laboratory spacecraft that the spacecraft shed just before entering the Mar...

This image covers a location that has been imaged several times to look for changes in gullies.

Mawrth Vallis has a rich mineral diversity, including clay minerals that formed by the chemical alteration of rocks or loose “regolith” (soil) by water.

This image shows the topography, with shading added, around the area where NASA's Curiosity rover landed on Aug. 5 PDT (Aug. 6 EDT).

The large impact crater known as Stickney is the largest crater on the Martian moon Phobos.

The yellow-white cloud in the bottom-center of this image is a Mars "dust tower" — a concentrated cloud of dust that can be lofted dozens of miles above the surface. The blue-white plumes are water...

This HiRISE image shows a group of cones, shield-like features, and round mounds.

This image shows an outcrop of the south polar layered deposits (SPLD). The SPLD consist of layers of ice and admixed dust and make up the bulk of the dome-shaped Planum Australe.

The high resolution imaging science experiment (HiRISE) is one of six science instruments for NASA's Mars Reconnaissance Orbiter.

This image covers a "fresh-looking" impact crater with a diameter of about 2 kilometers (1.2 miles). 

This image from orbit covers an area about 460 meters (about 1,500 feet) across, in which carbonate minerals have been identified from spectrometer observations. Fractures and possible layers are v...