Spacecraft that land in dusty areas of Mars create dark blast zone patterns where bright dust is blown away by the landing. Continued high-resolution monitoring with the HiRISE show these dark patterns fade over time in a surprising way.

These sequences of HiRISE images span two and a half years, during which time the rover has driven away from its initial touchdown location, leaving its tracks behind, which themselves fade over time. The parachute can also be seen flapping around in the wind near the backshell landing site. The landing sites of other spacecraft hardware (sky crane and heat shield) also show fading over this time, presumably because bright dust is settling on the surface and masking the blast zones.

Scientists thought they could model this fading and predict how long it would take for the patterns to disappear entirely. However, the most recent image, taken just a few weeks ago, shows that the blast zones aren’t fading as quickly as they predicted: they may even be getting darker! This shows that we don’t yet fully understand the processes that move dust around on the Martian surface.

Understanding this better will help the HP³ instrument on the future Mars lander InSight model the interior heat flow of Mars, which will be affected by the brightness of the surface at its landing site.

Written by: Ingrid Daubar  (27 March 2015)