CAPE CANAVERAL, Florida – Scientists have discovered evidence of a relict glacier on Mars, estimated to be 6 kilometers long and up to 4 kilometers wide, near the planet’s equator. This discovery suggests that there may have been surface water ice on Mars in recent times, which could have significant implications for future human exploration.
The surface feature identified as a “relict glacier” is one of many light-toned deposits found in the region. While light-toned deposits typically consist of light-colored sulfate salts, this deposit exhibits many features of a glacier, including crevasse fields and moraine bands.
According to Dr. Pascal Lee, a planetary scientist with the SETI Institute and the Mars Institute, and the lead author of the study, the discovery is not of ice, but rather of a salt deposit that preserves the detailed morphologic features of a glacier. Lee believes that salt formed on top of a glacier, preserving the shape of the ice below, including details like crevasse fields and moraine bands.
The presence of volcanic materials in the region suggests that the sulfate salts might have formed and preserved a glacier’s imprint underneath. When freshly erupted pyroclastic materials come in contact with water ice, sulfate salts may form and build up into a hardened, crusty salt layer. With erosion removing the volcanic materials, a crusty layer of sulfates mirroring the glacier ice underneath became exposed, revealing a salt deposit with features unique to glaciers.
The discovery of a relatively young relict glacier in this location indicates that Mars experienced surface ice in recent times, even near the equator. While water ice is not stable at the very surface of Mars near the equator at these elevations, there is a chance that some of it might still be protected at shallow depths under the sulfate salts.
The presence of water ice at shallow depths in a low latitude location on Mars could have significant implications for science and human exploration. It could mean that equatorial locations could be viable for extracting water ice from the ground, which would provide warmer conditions for human exploration while still allowing access to ice.
Dr. Lee cautions that more work needs to be done to determine if and how much water ice might be present in this relict glacier and whether other light-toned deposits might also have or have had ice-rich substrates. Nonetheless, this discovery opens up the possibility of new avenues of exploration for Mars and future space missions.