Considerable amounts of water ice are found at its equator

Investigating the Mars Express more than 15 years agoEuropean Space AgencyEuropean Space Agency (ESA) observed the training Medusa fossaLocated atEquatorEquator of the planet. This region of Mars is known to be the largest sedimentary deposit on the planet. It extends continuously for more than 5,000 km, covering an area equivalent to India, and is composed of several geological formations. the windthe wind Measuring hundreds of kilometers in diameter and several kilometers in height. Located at the boundary between the Martian highlands and lowlands, these formations are probably the largest source of dust on Mars and one of the depositsdeposits The most extensive on the planet.

The enigmatic nature of the deposits beneath the Medusae fossa formation

At the time, radar data revealed massive deposits up to 2.5 kilometers deep. But, the data wasn’t clear enough to determine exactly what they were made of. If we assume that these may be icy deposits, scientists do not exclude that they were in reality dust, volcanic ash or a huge accumulation of volcanic ash. sedimentsediment blown by the wind.

In 2023, the same team again observed this interesting region of Mars. She reached conclusions that leave little doubt about the nature and composition of these underground deposits.

Using new data from the Marsis radar, scientists have discovered that the deposits Medusa fossa : ” were even thicker than previously thought: up to 3.7 kilometers thick “, explains Thomas Waters of the Smithsonian Institution, lead author of both studies. And to add that it is ” Interestingly, the radar signals match what we expect from ice layers and are similar to the signals we see from the polar caps of Mars, which we know is very ice-rich. ” The new results instead suggest layers of dust and ice, all topped by a protective layer several hundred meters thick of dry dust or ash.

A large amount of water

We are talking about huge amounts of snow. Indeed, if all the locked ice melted, it would cover the entire planet with a water layer 1.5 to 2.7 meters high: this part of Mars contains the most water, and enough to fill Earth’s Red Sea. These new data also cast doubt on the 2007 conclusion. Medusa fossaIf they were just huge piles of dust, volcanic ash, or wind-blown sediment, ” We expect them to collapse under their own weightco-author Andrea Cicchetti of Italy’s National Institute of Astrophysics explains. This would create something much denser than what we actually see MarsisMarsis. And when we modeled the behavior of various materials without ice, nothing replicated the properties of the medusae fossa structure: we needed ice. »

Implications and new issues in the history of the water cycle on Mars

Although Mars now appears as a barren world, the planet’s surface is full of signs that water was once abundant, including dry rivers, ancient ocean and lake beds, and water-carved valleys. ‘Water. We have also discovered significant reservoirs of water ice on Mars, such as Prachand Polar capsPolar capsThe GlaciersGlaciers Buried near the equator and near-surface ice that is embedded in the Martian soil.

Surprisingly, this latest analysis ” Medusae challenges our understanding of the formation of Fossae and raises as many questions as it answers “, says ESA mission scientist Colin Wilson Mars ExpressMars Express and trace gas orbiters. If it is water ice,” These massive deposits will change our understanding of the climate history of Mars and will be an attractive target for human exploration and exploration. roboticsrobotics of March ” For those looking for where the runoff on Mars went, these deposits are part of the answer!

Although Mars appears dry today, the discovery revives interest in the planet’s watery past and raises questions about its climate history. However, these deposits, buried under hundreds of meters of dust and sediment, are currently inaccessible and represent a challenge for future exploration.