Liquid water on Mars 742 million years ago

A meteorite from Mars shows that there was liquid water on that planet 742 million years ago.

11 million years ago, an asteroid hit Mars and launched pieces of the Red Planet through space. One of these pieces ended up crashing into Earth and is one of the few meteorites whose origin is known with certainty to be Mars. This meteorite was rediscovered in 1931 at Purdue University, located in West Lafayette, Indiana, United States and has since been known as “the Lafayette meteorite.”

In previous investigations of the Lafayette meteorite, it was found to have interacted with liquid water while on Mars. But a crucial question remained unanswered: when did this interaction with liquid water take place? An international team has recently determined the age of minerals from the Lafayette meteorite that formed when liquid water was present.

The team has been led by Marissa Tremblay of Purdue University.

Some Mars meteorites contain minerals that formed by interaction with liquid water while they were still on Mars. Therefore, dating these minerals can tell us when there was liquid water on or near the surface of Mars.

Tremblay and his colleagues dated these minerals to the Lafayette meteorite and have discovered that they formed 742 million years ago. This means that at that time there was liquid water in the Martian area where they formed.

The Lafayette Meteorite. (Photo: Purdue University)

In any case, the authors of the study do not believe that liquid water was abundant on the surface of Mars at that time. Instead, they believe that the water came from thawing permafrost (ice mixed with mineral particles) in the nearby subsurface, and that the thawing of permafrost was caused by magmatic activity that occasionally occurs on Mars. The widespread existence of liquid water on the surface of Mars corresponds to a much older period in Mars’ history.

The study is titled “Dating recent aqueous activity on Mars.” And it has been published in the academic journal Geochemical Perspectives Letters. (Fountain: NCYT by Amazings)