Today, Mars is popularly referred to as the “Red Planet” because its dry, dusty landscape is rich in iron oxide (also known as “rust”). Also, the atmosphere is extremely thin and cold, and there can be no water on the surface in any form other than ice. But as the Martian landscape and other evidence shows, Mars was once a very different place, with a warmer, denser atmosphere and water running on its surface.

For years, scientists have tried to determine how long natural objects have existed on Mars and whether they are periodic or permanent. Another important question is how much water was once on Mars and whether it is enough for life. 4.5 billion years ago, Mars may have had enough water to cover it with a global ocean up to 300 meters (almost 300 feet) deep, according to a new study by an international team of planetary scientists.

They say these conditions, along with organic molecules and other elements currently being dispersed into the solar system by asteroids and comets, suggest that Mars may be the first planet to harbor life in the solar system. The research was carried out by the Institute of the Physical Body of the University of Paris (IPGP), the Center for Star and Planetary Formation of the University of Copenhagen (StarPlan), and the ETH Zurich Institute of Geochemistry and Petrology (GeoPetro). and the Physics Institute of the University of Bern.

A paper was recently published describing their research and findings. Science Advances. As they point out in their paper, the terrestrial planets have experienced a significant period of asteroid impact (Late Heavy Bombardment) since they formed more than 4.5 billion years ago.

Because of these effects, it is believed that water and the building blocks for life (organic molecules) are dispersed throughout the solar system. However, the role of this period in the evolution of rocky planets in the inner Solar System – especially when it comes to the distribution of volatile elements like water – is still debated. For their work, an international group reported the variability of a chromium isotope (⁵⁴Cr) in Martian meteorites dating to this early period. These meteorites were then part of the Martian crust and were ejected by asteroid collisions that sent them into space.

In other words, the composition of these meteorites represents the original crust of Mars before the asteroids deposited water and various elements on the surface.

Since Mars does not have active plate tectonics like Earth does, the surface is not subject to continuous convection and circulation. Thus, meteorites launched from Mars billions of years ago offer a unique insight into what Mars was like shortly after the formation of planets in the Solar System.

As co-author Professor Bizzarro of the StarPlan Center said in a UCPH faculty press release:

“Plate tectonics on Earth erased all evidence of what happened in the first 500 million years of our planet’s history. Plates are constantly moving, reversing and collapsing inside our planet. By contrast, Mars does not have plate tectonics on the planet’s surface, keeping a record of the earliest history of the planet. “

measurement variability ⁵⁴ The team estimated the Cr in these meteorites about 4.5 billion years ago when they hit Mars and the amount of water they carried.

According to their results, there would be enough water in an ocean to cover the entire planet at a depth of at least 300 meters (~1,000 feet), and in some areas up to 1 kilometer (0.62 mi) deep. By comparison, there was very little water on Earth at the time because an object the size of Mars collided with the Earth, causing the Moon to form (ie, the big impact hypothesis). In addition to water, the asteroids also sent organic molecules such as amino acids (the building blocks of DNA, RNA, and protein cells) to Mars during the late heavy bombardment. As Bizarro explains, this means that life could exist on Mars while Earth was barren:

“This happened in the first 100 million years of Mars’ existence. After that period, something catastrophic for potential life on Earth happened. A giant collision between Earth and another Mars-sized planet is believed to have occurred. It was also an energetic collision that destroyed all potential life on Earth.”

This work is similar to a recent study that used the deuterium-hydrogen ratio of Martian meteorites to create models of atmospheric evolution. Their findings showed that Mars may have been covered in oceans while Earth was still a ball of molten rock. These and other questions regarding the geological and environmental evolution of Mars will be further explored this decade with robotic missions to Mars (followed by crewed missions in the 2030s). Source