A NASA spacecraft could have explored the edges of a sea from early March in 1997

The landing site sits on the spillway of an ancient sea that has experienced catastrophic floods released by the basement and sediments of the planet. This could potentially provide evidence of the livability of Martians, said Rodriguez, lead author of "The Landing Site of the 1997 Mars Pathfinder Spacecraft: Overflow Deposits from an Emerging Inland Sea of ​​Mars", in Nature Scientific reports.

Nearly half a century ago, the Mariner 9 spacecraft retrieved images of some of the largest channels in the solar system. The orbital observations of the gigantic canals suggested that they had been formed about 3.4 billion years ago by cataclysmic floods, much larger than those known until today on Earth. The prospect that abundant water once carved the Martian landscape has sparked a renewed interest in the possibility that life may have flourished on the planet.

To test the hypothesis of a mega flood in Mars, NASA deployed its first Martian rover; the Sojourner, aboard the 1997 Mars Pathfinder spacecraft that traveled to the red planet. NASA spent a total of $ 280 million on the mission, including the launcher and mission operations. The terrain within the rover's visual range includes river features suggesting extensive regional flooding. However, these features suggest floods at least 10 times shallower than those estimated with the help of images obtained in orbit. As a result, the mission was unable to rule out other controversial points of view, claiming that the flow of debris or lava could in fact have dominated the history of canal formation without significant releases. 'water.

"Our article shows a basin, an approximate area of ​​California, that separates most of the gigantic Martian canals from the Pathfinder landing site." Debris or lava flows would have filled it before To reach the Pathfinder landing site, the basin requires cataclysmic floods as the main mechanism for channel formation, "said Rodriguez.

"The basin is covered with sedimentary deposits whose distribution corresponds exactly to the alleged magnitude of the flood of potential catastrophic floods, which would have formed an inland sea," Rodriguez said. "This sea is about 250 kilometers upstream from the landing site of Pathfinder, an observation that reframes its paleogeographic framework as an integral part of a marine spillway, forming a land barrier separating the Inland Sea and the the northern ocean.

"Our simulation shows that the presence of the sea would have mitigated the cataclysmic floods, resulting in shallow overflows reaching the Pathfinder landing site and producing the bed shapes detected by the spacecraft," Rodriguez said.

The team's results indicate that the marine fallout contributed to the landscape detected by the satellite nearly 22 years ago and reconciles the mission's in situ geological observations with the decades of remote sensing flow channel investigations.

The sea is strangely similar to the Aral Sea on Earth, as in both cases there are no distinct coastal terraces. Its rapid regression on submerged shallow slopes resulted in rates of withdrawal before the shore too fast for terraces to form. The same process may partly explain the long-recognized lack of shorelines in the northern plains.

"Our numerical simulations indicate that the sea is quickly covered with ice and disappeared in a few thousand years because of its rapid evaporation and sublimation." Meanwhile, it remained liquid below its ice cover, "said Bryan Travis, principal investigator of PSI. a co-author in the paper.

"Contrary to what happens on Earth, this sea was probably fed by groundwaters.If the ancient aquifers were sources of life, marine sedimentary materials proposed on the landing site of Pathfinder could contain a record of this life, a place easily accessible by future missions, "said Rodriguez.

"An exciting observation is that the previously proposed North Sea and North Pacific Ocean share a maximum elevation of the Paleo shoreline, implying an underground connection, perhaps by ducts, between the two marine bodies shortly afterwards. This altitude correspondence forms a new observation that strongly favors the northern ocean hypothesis, "said Dan Berman, PSI 's senior scientist, co – author of the paper.

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More information:
J.A.P. Rodriguez et al. Landing site of the 1997 Mars Pathfinder satellite: overflow deposits from an early March inland sea, Scientific reports (2019). DOI: 10.1038 / s41598-019-39632-1