The Perseverance rover landed on Mars at the start of 2021. That December, researchers announced that the craft has discovered something “completely unexpected” on the red planet. At the American Geophysical Union Fall Meeting, mission scientists announced that rocks which were previously thought to be sedimentary are in fact the remnants of lava flow in the planet’s ancient lake.
The researchers note that the surprising discovery of lava flow will help them create a timeline for the Jezero Crater, the region of Mars where the ancient lake once sat.
The robot used a drill on the end of one of its arms to scrape away at the rock and reveal distinct crystals associated with igneous rock. “A good geology student will tell you that such a texture indicates the rock formed when crystals grew and settled in a slowly cooling magma — for example a thick lava flow, lava lake, or magma chamber,” said Perseverance project scientist Ken Farley.
According to the scientists, this rock was altered by water several times, making it invaluable in dating the area of the planet. The rover has collected four rock samples thus far, and plans to collect another 37. Once back on earth, these rocks can be analyzed and data with incredible accuracy. The next goal was for the researchers is to determine if the samples were molded by a cooling lake of lava or if they originated from a subsurface chamber of lava.
