Geological findings of the Perseverance robot in Martian soil

The robotic rover Perseverance, which arrived on the surface of Mars in February 2021, has already made enough revealing geological observations on Martian terrain for various groups of scientists to analyze them in the framework of their two studies and to multiply the publications of results of these. The results of four of these studies have now been published at the same time.

In the academic journal Science, Kenneth Farley (California Institute of Technology in the United States) and colleagues describe the geological formations on the floor of Jezero Crater and the rover’s operations on them. They have discovered that the crater floor is made up of igneous rocks later altered by water. The Perseverance collected samples of these rocks, which it now stores on board for possible return to Earth.

Also in Science, Yang Liu (NASA) and colleagues investigate the petrology and composition of the Séítah formation, the lowest exposed geologic unit. From Perseverance observations, they have found that these igneous rocks consist primarily of coarse-grained olivine, an igneous mineral, indicating that they formed during the slow cooling of a thick layer of magma. The composition of the rocks is similar to that of some Martian meteorites.

In the academic journal Science Advances, Svein-Erik Hamran (University of Oslo in Norway) and colleagues analyze a continuous radar scan captured by Perseverance during its initial 3-kilometer run, revealing the crater’s bedrock stratigraphy and electromagnetic properties to a depth of about 15 meters below the surface. They suggest that the layered structure under the crater floor may indicate a history of igneous activity and repeated exposure to liquid water.

One of the plots inspected by the Perseverance robot. (Photo: NASA JPL / Caltech)

Also in Science Advances, Roger Wiens (Los Alamos National Laboratory) and colleagues analyze observations from Perseverance’s remote sensing instrument during its first 286 days on the Red Planet, revealing a volcanic terrain with rocks stratified beneath the surface by density and composition. They have found that the lower stratigraphic rock layers are richer in normative pyroxene and that the lowest layer observed is rich in olivine with the highest density observed. (Source: AAAS)