A NASA spacecraft is providing new evidence of a wet underground environment on Mars that adds to an increasingly complex picture of the Red Planet’s early evolution.
Scientists are on the verge of discovering whether there is life on Mars based on new data collected by NASA’s Reconnaissance Orbiter.
Prof John Parnell, 55, has co-written a theory with Dr Joseph Michalski, a planetary geologist at the Natural History Museum, that suggests they have discovered the best signs of life in the huge McLaughlin Crater on the surface of Mars.
Scientists believe the discovery of minerals below the Red Planet’s surface is the “strongest evidence yet” it may have supported life.
The Martian crater is 57 miles (92 kilometers) in diameter and 1.4 miles (2.2 kilometers) deep.
McLaughlin’s depth apparently once allowed underground water, which otherwise would have stayed hidden, to flow into the crater’s interior.
Layered, flat rocks at the bottom of the crater contain carbonate and clay minerals that form in the presence of water. McLaughlin lacks large inflow channels, and small channels originating within the crater wall end near a level that could have marked the surface of a lake.
Speaking from his laboratory at the University of Aberdeen, geochemist Prof Parnell said: “We could be so close to discovering if there is, or was, life on Mars.
“There can be no life on the surface of Mars because it is bathed in radiation and it’s completely frozen. However, life in the sub surface would be protected from that.”
A report published in Geo Science journal suggests that based on this evidence, bacteria or other microbes were or still are living under the surface of Mars.
Joseph Michalski, lead author of the report, said: “Taken together, the observations in McLaughlin Crater provide the best evidence for carbonate forming within a lake environment instead of being washed into a crater from outside.”
Spectrometer for Mars (CRISM) on MRO to check for minerals such as carbonates, which are best preserved under non-acidic conditions.
“A number of studies using CRISM data have shown rocks exhume from the subsurface by meteor impact were altered early in Martian history, most likely by hydrothermal fluids,” Michalski said.
Michalski added: “Exploring these rocks on Mars, where the ancient geologic record is better preserved than on Earth, would be like finding a stack of pages that have been ripped out of Earth’s geological history book.”
McLaughlin Crater sits at the low end of a regional slope several hundreds of miles long on the western side of the Arabia Terra region of Mars.
As on Earth, groundwater-fed lakes are expected to occur at low regional elevations. Therefore, this site would be a good candidate for such a process.
Launched in 2005, the Mars Reconnaissance Orbiter and its six instruments have provided more high-resolution data about the Red Planet than all other Mars orbiters combined.
“This new report and others are continuing to reveal a more complex Mars than previously appreciated, with at least some areas more likely to reveal signs of ancient life than others,” said Rich Zurek, Mars Reconnaissance Orbiter Project Scientist.