A team of US scientists has developed a new approach to determine how dusty Mars ice really is, and whether it could melt.
Mars is a dusty planet, so much of its ice is also dusty and much darker than fresh snow we might see on Earth. The dustier the ice is, the darker and thus warmer the ice gets, which can affect both its stability and evolution through time. Under certain conditions, this might also mean that the ice could melt on Mars.
The team from Universities of Arizona State and Washington combined data from NASA's Phoenix Mars Lander and Mars Reconnaissance Orbiter with computer simulations to successfully match the brightness of Martian ice and determine its dust content.
Their results have been published in the Journal of Geophysical Research: Planets.
"There is a chance that this dusty and dark ice might melt a few centimetres down. And any subsurface liquid water produced from melting will be protected from evaporating in Mars' wispy atmosphere by the overlying blanket of ice," said Aditya Khuller, a planetary scientist at Arizona State University.
Based on their simulations, the team predicted that the ice dug up by the Phoenix Mars Lander formed by dusty snowfall, sometime over the last million years, similar to other ice deposits found previously across the mid-latitudes of Mars.
"It is widely believed that Mars has experienced multiple ice ages throughout its history, and it looks like the ice being exposed throughout the mid-latitudes of Mars is a remnant of this ancient dusty snowfall," Khuller said.
For next steps, the team hopes to further analyse ice exposures on Mars, assess if the ice could actually melt, and learn more about Mars' climate history.
"We are working on developing improved computer simulations of Martian ice to study how it evolves over time, and whether it might melt to form liquid water," Khuller said.
"The results from this study will be integral to our work because knowing how dark the ice is directly influences how warm it gets."