Telltale Signs of an Equatorial Glacier on Mars

This is cool:

“What we’ve found is not ice, but a salt deposit with the detailed morphologic features of a glacier,” lead study author Dr. Pascal Lee, a senior planetary scientist with the SETI Institute and the Mars Institute, said in a statement. 

“What we think happened here is that salt formed on top of a glacier while preserving the shape of the ice below, down to details like crevasse fields and moraine bands.” 

The researchers believe the glacier was 3.7 miles (6 kilometers) long and 2.5 miles (about 4 kilometers) wide, with an elevation between 0.8 to 1.1 miles (1.3 to 1.7 kilometers). 

Scientists have an idea of how the imprint of the glacier came to be, based on evidence of volcanic material in the region. When mixtures of volcanic ash, lava and volcanic glass called pumice react with water, a hard, crusty salt layer can form. 

“This region of Mars has a history of volcanic activity. And where some of the volcanic materials came in contact with glacier ice, chemical reactions would have taken place at the boundary between the two to form a hardened layer of sulfate salts,” said study coauthor Sourabh Shubham, a doctoral student of geology at the University of Maryland, College Park, in a statement.