Mars Glacier is a glacier

Glacier

A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...

 in the southeast corner of Alexander Island

Alexander Island

Alexander Island or Alexander I Island or Alexander I Land or Alexander Land is the largest island of Antarctica, with an area of lying in the Bellingshausen Sea west of the base of the Antarctic Peninsula, from which it is separated by Marguerite Bay and George VI Sound. Alexander Island lies off...

, 6 nautical miles (11 km) long and 2 nautical miles (3.7 km) wide, flowing south into the ice shelf

Ice shelf

An ice shelf is a thick, floating platform of ice that forms where a glacier or ice sheet flows down to a coastline and onto the ocean surface. Ice shelves are only found in Antarctica, Greenland and Canada. The boundary between the floating ice shelf and the grounded ice that feeds it is called...

 of George Vl Sound between Two Step Cliffs

Two Step Cliffs

Two Step Cliffs is the eastern face of a flat-topped sedimentary mountain, 680 m, immediately east of Mars Glacier on the east coast of Alexander Island. First seen from the air by Lincoln Ellsworth on November 23, 1935, and mapped from photos obtained on that flight by W.L.G. Joerg...

 and Phobos Ridge

Phobos Ridge

Phobos Ridge is a rocky ridge of sandstones and shales forming the west side of Mars Glacier in the southeast corner of Alexander Island. The coast in this vicinity was first seen from the air by Lincoln Ellsworth on November 23, 1935, and roughly mapped from photos obtained on that flight by...

. First seen from the air by Lincoln Ellsworth

Lincoln Ellsworth

Lincoln Ellsworth was an arctic explorer from the United States.-Birth:He was born on May 12, 1880 to James Ellsworth and Eva Frances Butler in Chicago, Illinois...

 on November 23, 1935, and roughly mapped from photos obtained on that flight by W.L.G. Joerg. First surveyed in 1949 by the Falkland Islands Dependencies Survey (FIDS) and named by the United Kingdom Antarctic Place-Names Committee (UK-APC) for the planet Mars.