Glacier - Glaciers On Mars

Glaciers On Mars

Elsewhere in the solar system, deposits surrounding the polar ice caps of Mars show geologic evidence of glacial deposits. Especially the south polar cap is compared to glaciers on Earth. Other glacial features on Mars are glacial debris aprons and the lineated valley fills of the fretted terrain in northern Arabia Terra and eastern Hellas Planitia. Topographical features and computer models indicate the existence of more glaciers in Mars' past.

Martian glaciers at mid-latitudes, between 35 and 65° North or South, are affected by the thin atmosphere of Mars. Because of the low atmospheric pressure, ablation near the surface is solely due to sublimation, not melting. As on Earth, many glaciers are covered with a layer of rocks which insulates the ice. A radar instrument on board the Mars Reconnaissance Orbiter found ice under a thin layer of rocks in formations called Lobate Debris Aprons (LDA's).

• Gullies in a crater in Eridania quadrangle, north of the large crater Kepler. Also, features that may be remains of old glaciers are present. One, to the right, has the shape of a tongue. Image was taken by the Mars Global Surveyor under the Public Target program.

• Lobate Debris Apron in Phlegra Montes, Cebrenia quadrangle. The debris apron is probably mostly ice with a thin covering of rock debris, so it could be a source of water for future Martian colonists. Scale bar is 500 meters long. Image was obtained by HiRISE.

• Moreux Crater moraines and kettle holes, as seen by HiRISE. Location is Ismenius Lacus quadrangle.

• Mesa in Ismenius Lacus quadrangle, as seen by CTX. Mesa has several glaciers eroding it. One of the glaciers is seen in greater detail in the next two images from HiRISE.

• Glacier as seen by HiRISE under the HiWish program. Area in rectangle is enlarged in the next photo. Zone of accumulation of snow at the top. Glacier is moving down valley, then spreading out on plain. Evidence for flow comes from the many lines on surface. Location is in Protonilus Mensae in Ismenius Lacus quadrangle.

• Enlargement of area in rectangle of the previous image. On Earth the ridge would be called the terminal moraine of an alpine glacier. Picture taken with HiRISE under the HiWish program. Location is Ismenius Lacus quadrangle.

• The arrow in the left picture points to a possibly valley carved by a glacier. The image on the right shows the valley greatly enlarged in a Mars Global Surveyor image.

• Context for the next image of the end of a flow feature or glacier. Location is Hellas quadrangle. Picture taken with HiRISE under the HiWish program.

• Close-up of the area in the box in the previous image. This may be called by some the terminal moraine of a glacier. For scale, the box shows the approximate size of a football field. Image taken with HiRISE under the HiWish program. Location is Hellas quadrangle.

• Tongue-Shaped Glacier, as seen by Mars Global Surveyor. Location is Hellas quadrangle.

• Possible moraine on the end of a past glacier on a mound in Deuteronilus Mensae, as seen by HiRISE, under the HiWish program.

• Glaciers, as seen by HiRISE, under HiWish program. Glacier on left is thin because it has lost much of its ice. Glacier on the right on the other hand is thick; it still contains a lot of ice that is under a thin layer of dirt and rock. Location is Hellas quadrangle.