Over 15 years ago ESA's Mars Express spacecraft studied the Fossae Formation of Medusae and revealed mysterious deposits up to 2.5 km deep. These early observations left it unclear what the sediment was made of, but a new study provides an answer.
This image shows a height map of the surface of Mars, with the lowest land areas shown in blue and the highest land areas shown in white. Image credit: ESA.
of Formation of medusae fossa (MFF) – a huge and unusual soft rock deposit near Mars' equator – is about one-fifth the size of the continental United States and 100 times the mass of the largest explosive volcanic deposits on Earth.
It consists of several wind-carved features hundreds of kilometers in diameter and several kilometers high.
This feature, discovered at the boundary between highlands and lowlands on Mars, is probably the largest single source of dust on Mars.
Initial observations from ESA's Mars Express spacecraft show that the MFF is relatively transparent to radar and has low density, both characteristics seen in ice deposits.
But planetary scientists couldn't rule out the possibility that the terrain is actually drier, a huge accumulation of windblown dust, volcanic ash, or sediment.
“When we reexamined the MFF using new data from Mars Express's MARSIS radar, we found that the deposits were even thicker than we thought,” said Dr. Thomas Watters, a planetary researcher at the Smithsonian Institution. It's up to 3.7 kilometers thick,” said Dr. Thomas Watters, a planetary researcher at the Smithsonian Institution.
“Interestingly, the radar signal is consistent with what we would expect to see from layered ice, and is similar to the signal seen from the polar caps of Mars, which we know are very ice-rich.”
“If it were to melt, the ice trapped in the MFF would cover the entire planet in a layer of water 1.5 to 2.7 meters deep. This would be the largest amount of water ever discovered in this region of Mars. That's enough to fill Earth's Red Sea.”
“This is where the new radar data comes in. Given its depth, if the MFF is just a huge dust pile, we would expect it to be compressed under its own weight,” says the Italian National Institute of Astrophysics. said researcher Dr. Andrea Cicchetti.
“This will produce something much denser than what we're actually seeing with MARSIS.”
“And when we modeled how different materials behave without ice, nothing reproduced the properties of MFF. We need ice.”
“The new results suggest that there is instead a layer of dust and ice, topped by a protective layer of dry dust or ash hundreds of meters thick.”
In this image, the white line on Mars' surface (top) indicates the stretch of land scanned by Mars Express's MARSIS radar. The graph below shows the topography and subsurface structure of the land, with layers of dry sediment (likely dust or volcanic ash) shown in brown and layers of likely ice-rich sediment shown in blue. I am. The graph shows that the ice deposits are thousands of meters high and hundreds of kilometers wide. Once all the suspected water ice in the MFF melts, Mars will be covered by an ocean of water up to 2.7 meters deep. Image credit: CReSIS / KU / Smithsonian Institution.
“This latest analysis challenges our understanding of the MFF and raises as many questions as it answers,” said ESA Project Scientist for Mars Express and the ESA ExoMars Trace Gas Orbiter. said Dr. Colin Wilson.
“How long ago did these ice deposits form? What was Mars like at that time?”
“If confirmed to be water ice, these giant deposits could change our understanding of Mars' climate history.”
“Any ancient water reservoir would be an attractive target for human or robotic exploration.”
Result is, journal Geophysical Research Letters.
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thomas watters other. 2024. Evidence for ice-rich layered deposits in the Medusa Fossa Formation on Mars. Geophysical Research Lettersin press.
Source: www.sci.news
