Groundwater May Have Played Important Role in Shaping Mars

By Nancy Atkinson - December 11, 2008 at 7:25 AM UTC | Planetary Science
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Scientists have been intrigued and puzzled by light-toned layered deposits on Mars since the Mariner spacecraft flybys in the early 1970s. Known as LTDs (Light Toned Deposits), they are Martian sediments that most closely resemble sediments on Earth and are some of the most mysterious features on Mars. Causes for their origin remain unknown, and different mechanisms, including volcanic processes, have been proposed for their formation. But recently data and images from Mars Express suggest that several LTDs were formed when large amounts of groundwater burst on to the surface. Scientists propose that groundwater had a greater role in shaping the Martian surface than previously believed, and may have sheltered primitive life forms as the planet started drying up.

LTDs were some of the first features seen on Mars, because they showed up even in the black and white images sent back by the first spacecraft to flyby Mars. But they are also some of the least understood features on the Red Planet, and have been highly debated. These deposits occur on a large scale in Arabia Terra, Chaotic Terrain and Valles Marineris, close to the Tharsis volcanic bulge.

Now, based on Mars Express data, scientists propose that these sediments are actually younger than originally believed. Angelo Rossi and several colleagues report their findings in a paper published in September of this year in Geophysical Research. They have proposed that several LTDs may have been deposited by large-scale springs of groundwater that burst on to the surface, possibly at different times.

Analysis also indicates that ground water had a more wide-ranging and important role in Martian history than previously believed. Hydrated minerals, relatively young in age, have been found in the region.

Given that the deposits are relatively young in age, and associated with water, they may also have sheltered microbial life from the drier and harsher climate in more recent times on Mars, possibly eliminating the need for a stable atmosphere or a permanent water body.

Complimentary studies by the Mars Reconnaissance Orbiter

also have indicated LTDs were formed by water.

Source:

ESA

Nancy Atkinson

Nancy Atkinson

Nancy Atkinson is a space journalist and author with a passion for telling the stories of people involved in space exploration and astronomy. She is currently retired from daily writing, but worked at Universe Today for 20 years as a writer and editor. She also contributed articles to The Planetary Society, Ad Astra (National Space Society), New Scientist and many other online outlets.

Her 2019 book, "Eight Years to the Moon: The History of the Apollo Missions,” shares the untold stories of engineers and scientists who worked behind the scenes to make the Apollo program so successful, despite the daunting odds against it. Her first book “Incredible Stories From Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos” (2016) tells the stories of 37 scientists and engineers that work on several current NASA robotic missions to explore the solar system and beyond.

Nancy is also a NASA/JPL Solar System Ambassador, and through this program, she has the opportunity to share her passion of space and astronomy with children and adults through presentations and programs. Nancy's personal website is nancyatkinson.com