February 13, 2017
Mars was just slammed by a ‘cosmic shotgun blast’
Nobody ever said it was going to be easy, but the discovery of a cluster of recent meteorite impacts on Mars has highlighted a major reason why future colonization of the Red Planet will be an almighty challenge.
Among myriad other obstacles, Mars has lower gravity, lower temperatures, and lower atmospheric pressure compared to Earth. A new observation from NASA's Mars Reconnaissance Orbiter has also reminded us that while Earth's thicker atmosphere keeps out almost all space rocks, the thinner atmosphere on Mars gives less such protection.The orbiter returned images of a pale landscape dotted with dark blemishes. Close inspection revealed that the marks of dozens of impacts were clustered around a small area in the Tharsis region of Mars.
The impact is thought to have occurred between 2008 and 2014, but NASA's High-Resolution Imaging Science Experiment (HiRISE) camera revealed in 2016 that two large impact craters were surrounded by up to 30 smaller craters.
A meteorite had broken up in the atmosphere and then rained down rock onto the surface.
Meteorite impacts are helpful, for now
This is by no means the first observation of impacts of this nature. Regular examination of impact sites on Mars help scientists to study what minerals sit beneath the surface, and to track how surface winds affect fine particles of material. The regularity of impacts is also of great interest.
Human expeditions to Mars are expected within two or three decades, and Elon Musk of Space X previously said he wants to help the human race to establish a permanent, self-sustaining colony on Mars within the next 50 to 100 years. Whoever does make it up there, though, will have to find a way to deal with what amounts to celestial carpet bombing.
Image credit: NASA/JPL/University of Arizona