The hunt for potentially vital waters under Mars

Ground-penetrating radar has already helped scientists discover liquid water beneath the surface of Mars. It could also be the key to discover if life exists in our cosmic neighbor.

With NASA's Curiosity robot in the limelight, with captivating selfies and stunning panoramic images of the red planet, it's easy to forget the six active satellites orbiting Mars and continue their work silently.

But one of them, Mars Express from the European Space Agency (ESA), recently made headlines when researchers uncovered the most compelling evidence of the presence of the world 's best. liquid water on Mars.

This water was not in a pond on the surface that the researchers missed by chance. It hid 1.5 km under the south pole of Mars, forming a shallow lake 20 km long.

Life on Mars?

Led by Assistant Professor Roberto Orosei of the National Institute of Astrophysics in Bologna, Italy, the ESA team discovered the lake by thoroughly analyzing the measurements of a lake. radar instrument called MARSIS boarded the satellite.

MARSIS sends radio waves to the planet that enters the ground. These waves are reflected in different ways depending on whether they hit the rock, ice or water.

"The echoes are much stronger, sometimes stronger than those from the top of the ice, when liquid water lies under the ice sheet," reveals Roberto.

The lake is deep underground and must be very salty to prevent it from freezing because it is covered with carbon dioxide, which freezes at -125 ° C. Nevertheless, some experts believe that the discovery gives hope that life could persist there.

Of course, if life does not exist in similar environments on Earth, hopes will be broken. Yet only a few months ago, two equally deep, salty underground lakes had been discovered beneath the Devon Ice Cap in the Canadian Arctic. Once again, the discovery was made using a penetrating radar in the ground.

If researchers dig into these arctic depths and discover a unique and hidden microbial community, as in other underground lakes, the rationale for life existing in Mars Lake will be much stronger, though a mission is to dig 1.5 km to prove it. would be fraught with difficulties.

Drone swarms

Back on Earth, ground penetrating radar is used in many industries. In civil engineering in particular, radar helps monitor our complex underground railways, roads, tunnels, bridges and utility networks.

And it is also valuable for mining exploration. Radar helps to plan mines that exploit the rich bauxite deposits of Australia, the world's leading source of aluminum. It is also a useful tool in coal, zinc and nickel mines.

But according to Dr. Jan Francke, founder of Groundradar and researcher with nearly 30 years of experience in the field, the radar will soon be able to do a lot more.

He thinks the new radar concepts developed by the Australian AMIRA International Mining Research Organization are "only at 12 or 18 months". These technologies would bring back an antenna from 5 m to 10 cm only.

"If you combine this concept with new low-cost transmitters and receivers or satellite imaging technology such as hyperspectral cameras, we could mount them on a cloud of drones flying at low altitude to scan large areas. In 3D."

This would provide high-resolution underground detail that allows for deeper mineral removal much more efficiently.

Could similar swarms of drones be used to search for more underground lakes potentially carrying life on Mars?

NASA is funding an exploratory study on the use of bee-like drones to study the red planet. If these drones were equipped with tiny radars penetrating into the ground, we could find underground lakes much closer to the surface – lakes on which we could bury ourselves more easily to finally find out if life exists under the ice of our cosmic neighbor. .

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Image: Radar footprints on the buried lake of the planet Mars