Mars has not always been a dusty and barren planet.
Previous modeling has shown that the planet once overflowed with water that eventually retreated below the surface. But new research details the first direct geological evidence of a "planetary groundwater system" explaining the aquatic history of Mars and providing new sites for future life-hunting missions.
The revelations come from brave geologists and Mars Express Orbiter from the European Space Agency. The probe, launched in 2003, constantly rotates around the planet and is equipped with a number of high-resolution cameras constantly capturing images of the Martian surface. Researchers from the University of Utrecht, led by Francesco Salese, have explored these images and have studied with interest 24 deep craters in the northern hemisphere of Mars, looking for signs indicating that the Water had flowed there formerly.
Their findings, published in the Journal of Geophysical Research: Planets, show that almost all of these craters give signs that they have already contained flowing water. This has led researchers to believe that a water reserve that was stuck between 4,000 and 5,000 meters below sea level was once on Mars.
"Early March was an aquatic world, but as the climate of the planet has changed, this water has been withdrawn beneath the surface to form pools and" groundwater, "Salese said in a press release.
"We traced this water in our study because its scale and role are the subject of debate, and we discovered the first geological evidence of an underground water system at the site. scale of the planet on Mars. "
Craters have a wide variety of features: water-carved canals in their walls, signs of valley valleys formed by erosion, and shorelines and terraces created by stagnant water. There were also traces of deltas – formed by the slow drops of water – in 15 of the 24 craters. The researchers found no evidence of water coming from outside the craters, which led them to believe that they were fed from the base.
Because each crater had geological remains of water activity between approx. The team suggests between 4,000 and 4,800 meters the idea that all the craters they studied may have been connected by the same groundwater system – although they can only be certain based on of this evidence.
Be that as it may, water signs herald the potential discovery of life – or its remnants – on the red planet.
"Such discoveries are extremely important, helping us to identify the most promising areas of Mars to find signs of past life," said Dmitri Titov, Mars Express Project Scientist.
And evidence of the presence of water on Mars continues to accumulate, suggesting that the planet may even contain liquid water today. In July 2018, scientists studied the southern ice cap using the radar of the Mars Express orbiter. They discovered that the cap could. On February 19, another team suggested , creating an underground lake that can support life.
Noting that life will be at the center of many missions in the future,, which is expected to land on Mars in 2020.