Debris from ancient volcanic eruptions on Mars could offer new insights into the search for alien life, according to a recent study. The research highlights a newly discovered rock type found at the future landing site of the ExoMars Rosalind Franklin rover mission, scheduled for launch in 2028.
Published in the Journal of Geophysical Research: Planets, the study utilized data from orbiting satellites to analyze rocks scattered across a 19,300 square mile (50,000 square kilometers) area. Researchers concluded that these rocks were likely deposited from the atmosphere, potentially as volcanic ash, billions of years ago, despite the absence of known volcanoes in the vicinity.
Emma Harris, the study's first author and a doctoral student at the Natural History Museum in London, noted, "There are no known volcanoes at this site, which means the debris probably came from hundreds or maybe even thousands of kilometers away." The study suggests that an explosive volcanic event could have propelled ash high into the atmosphere, allowing it to settle over a vast distance.
Scientists believe the dark rocks may have shielded mineral-rich formations beneath, which could preserve signs of ancient life. However, the exact formation process of these surface rocks remains unclear.
Using data from the Context Camera on the Mars Reconnaissance Orbiter, researchers mapped the region and theorized that the dark rocks once covered the entire site but are now found only in smaller patches. They propose that groundwater upwelling in impact craters may have contributed to the preservation of the ash.
The ExoMars Rosalind Franklin rover will not traverse the jagged dark rocks but aims to access mineral-rich deposits at their edges. The mission has faced delays, notably due to geopolitical tensions affecting partnerships between the European Space Agency (ESA) and Russia's Roscosmos.
In May 2024, NASA rejoined ESA to complete the mission, which originally began over two decades ago. The rover will drill up to 6.6 feet (2 meters) into the Martian surface to collect and analyze ancient rocks, which researchers believe are key to uncovering signs of life on the planet.
Harris emphasized the importance of studying these ancient formations, stating, "If life ever existed on Mars, it would have been a very long time ago because the planet has been arid and fairly inactive for the past three billion years. So we want to look at rocks before this period to see if there are traces of water or microbial life."