HiWish is a program created by NASA so that anyone can suggest a place for the HiRISE camera on the Mars Reconnaissance Orbiter to photograph.
Selected images released were used for three talks at the 16th Annual International Mars Society Convention.
[10] The radial and concentric cracks visible here are common when forces penetrate a brittle layer, such as a rock thrown through a glass window.
Ice being less dense than rock, pushed upwards on the surface and generated these spider web-like patterns.
The dunes are covered by a seasonal carbon dioxide frost that forms in early autumn and remains until late spring.
Extraterrestrial sand seas such as those found on Mars are referred to as "undae" from the Latin for waves.
Martian gullies are small, incised networks of narrow channels and their associated downslope sediment deposits, found on the planet of Mars.
First discovered on images from Mars Global Surveyor, they occur on steep slopes, especially on the walls of craters.
Much of the Martian surface is covered with a thick ice-rich, mantle layer that has fallen from the sky a number of times in the past.
[37][38] The Phoenix (spacecraft) discovered water ice with made direct observations since it landed in a field of polygons.
Places on Mars that display polygonal ground may indicate where future colonists can find water ice.
These depressions contain water ice in the straight wall that faces the pole, according to the study published in the journal Science.
A typical scalloped depression displays a gentle equator-facing slope and a steeper pole-facing scarp.
Scalloped depressions are believed to form from the removal of subsurface material, possibly interstitial ice, by sublimation.
[66] On November 22, 2016, NASA reported finding a large amount of underground ice in the Utopia Planitia region of Mars.
[68][69] The volume of water ice in the region were based on measurements from the ground-penetrating radar instrument on Mars Reconnaissance Orbiter, called SHARAD.
[73][74][75][76] Ring mold craters are believed to be formed from asteroid impacts into ground that has an underlying layer of ice.
However, with more extensive analysis of larger areas, it was found the ring mold craters are sometimes formed where there is not as much ice underground.
They have even blown dust off the solar panels of two Rovers on Mars, thereby greatly extending their useful lifetime.
It freezes out directly onto the surface of the permanent polar cap, which is made of water ice covered with layers of dust and sand.
By the time temperatures rise in the spring, the frost layer has become a slab of semi-transparent ice about 3 feet thick, lying on a substrate of dark sand and dust.
This dark material absorbs light and causes the ice to sublimate (turn directly into a gas).
Remnants of a 50–100 meter thick mantling, called the upper plains unit, has been discovered in the mid-latitudes of Mars.
[102][103] Large areas of the Martian surface are loaded with ice that is protected by a meters thick layer of dust and other material.
[104][105] In a short time, the ice will disappear into the cold, thin atmosphere in a process called sublimation.
On Mars sublimation has been observed when the Phoenix lander uncovered chunks of ice that disappeared in a few days.
Periods of high tilt will cause the ice in the polar caps to be redistributed and change the amount of dust in the atmosphere.
[115] Sites like this may have recently had held liquid water, hence they may be fruitful places to search for evidence of life.
So-called "rootless cones" are caused by explosions of lava with ground ice under the flow.
To suggest a location for HiRISE to image visit the site at http://www.uahirise.org/hiwish In the sign up process you will need to come up with an ID and a password.