MRO Data Reveals A Once Deep, Cratered Lake on Mars

Sedimentary Layers from “Lake McLaughlin”
Credit: JPL

Source: JPL

Launched in 2005 aboard an Atlas V 401, the Mars Reconnaissance Orbiter has provided a wealth of information regarding the presence of water ice on the Red Planet.  In an article   (abstract) published Sunday in Nature Geoscience,  a team of researchers analyzing  data from MRO’s CRISM instrument (Compact Reconnaissance Imaging Spectrometer), which was used to image the McLaughlin Crater, has concluded that the crater most likely once held a lake fed by underground water.  Deep craters such as McLaughlin present the opportunity to study ejected materials which were once far below the surface, offering a view into the planet’s past.

What is particularly noteworthy in this case, is that CRISM instrument identified the presence of carbonate and clay minerals,  which form in the presence of water.  Taken together, and with absence of large water carved valleys leading into the crater, but a series of much smaller, local channels consistent with what would  be a shoreline, and it paints a picture of a stable, cratered lake which was a fairly isolated environment replenished by groundwater. In other words, a nearly ideal environment to foster the conditions for life, and one which is quite different other areas on Mars which suggest more acidic,  “water-limited environments.”

The discovery, which could indicate the presence, at least in the past, of a very active subsurface water environment,  along with many others made by analyizing images from MRO, such as possible periodic flowing salty water in the form of a freeze resistant brine, and 99% pure water ice  in mid-latitudes,  adds to a growing body evidence that while hardly a water planet,  Mars may still  be much wetter than once thought.

Taken together with recent radiation observations from the Curiosity rover,  which reveal very manageable levels of surface radiation,  it is difficult to escape the conclusion that even if Mars did not habor life in the past, it certainly can in the future.