Evidence of ancient rivers on Mars. By Dmytr0 (Own work) [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons |
Extensive systems of fossilized river beds have been discovered in an ancient area of the surface of Mars, supporting the existence of a warm and wet environment billions of years ago. Isn’t it possible that if there was water and a warm climate, life flourished on Mars just as it did on Earth?
The study, conducted by University College London and published in
Geology, identified more than 17,000 kilometers of ancient riverbeds
located on a plain in the northern parts of the Red Planet called Arabia
Terra, providing groundbreaking evidence that extensive water existed
on Mars.
“Climate models of early Mars predict rain in Arabia Terra and until
now there was little geological evidence on the surface to support this
theory. This led some to believe that Mars was never warm and wet but
was a largely frozen planet, covered in ice sheets and glaciers. We’ve
now found evidence of extensive river systems in the area which supports
the idea that Mars was warm and wet, providing a more favorable
environment for life than a cold, dry planet,” explained lead author,
Joel Davis (UCL Earth Sciences).
Perspective
view of Aram Dorsum, an inverted channel on Mars and candidate landing site for
the ExoMars rover. Credit: NASA/JPL/MSSS |
But for deeds, researchers have speculated and even identified
valleys and channels on Mars that they believe were carved and show
signs of erosion, caused by rain and liquid water just as it occurs on
Earth.
However, these structures were not identified until researchers
decided to analyze high-resolution images provided by NASA’s spacecraft
the MRO.
The new study examined an area of land approximately the size of Brazil.
Topographic
map of Mars. Arabia Terra is an ancient region that connects the southern
highlands and the northern lowlands. Credit: NASA/JPL/MOLA Science Team |
However, researchers examined the area with a never before resolution
equaling 6 meters-per-pixel, compared to previous 100 meters-per-pixel.
In addition to a few valleys, the team revealed the existence of many
systems of fossilized river beds visible as inverted channels spread
across the Arabia Terra plain.
Interestingly, scientists say these channels ar eerily similar to those found on Earth and other parts of Mars.
Comparing the discovery to Earth, researchers say that on Earth,
inverted channels often occur in dry, desert environments like Oman,
Egypt.
Aerial
view of inverted channels on the Earth, south-west of the Green River, Utah.
Credit: Rebecca Williams |
“The networks of inverted channels in Arabia Terra are about
30 metres high and up to 1-2 kilometres wide, so we think they are
probably the remains of giant rivers that flowed billions of years ago.
Arabia Terra was essentially one massive floodplain bordering the
highlands and lowlands of Mars. We think the rivers were active
3.9-3.7 billion years ago, but gradually dried up before being rapidly
buried and protected for billions of years, potentially preserving any
ancient biological material that might have been present,” added Joel
Davis.
“These ancient Martian flood plains would be great places to explore
to search for evidence of past life. In fact, one of these inverted
channels called Aram Dorsum is a candidate landing site for the European
Space Agency’s ExoMars Rover mission, which will launch in 2020,” said
Dr. Matthew Balme, Senior Lecturer at The Open University and co-author
of the study.
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