Phobos Ridge is a rocky ridge of sandstones and shales forming the west side of Mars Glacier

Mars Glacier

Mars Glacier is a glacier in the southeast corner of Alexander Island, 6 nautical miles long and 2 nautical miles wide, flowing south into the ice shelf of George Vl Sound between Two Step Cliffs and Phobos Ridge. First seen from the air by Lincoln Ellsworth on November 23, 1935, and roughly...

 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...

. The coast in this vicinity was 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. This ridge was first surveyed in 1949 by the Falkland Islands Dependencies Survey (FIDS) and named by the United Kingdom Antarctic Place-Names Committee (UK-APC) for its association with Mars Glacier, Phobos being the inner of the two satellites of Mars.