This image shows: NASA’s Perseverance Mars rover took this selfie on July 23, 2024, the 1,218th Martian day, or sol, of the mission. To the left of the rover near the center of the image is the arrowhead-shaped rock nicknamed “Cheyava Falls,” which has features that may bear on the question of whether Mars was home to microscopic life in the distant past. The small dark hole in the rock is where Perseverance took a core sample, which is now in a sample tube stored in the rover’s belly. The white patch to the right of the hole is where the rover used an abrasion tool to clear away the top surface, allowing science instruments to study the rock’s composition. NASA’s Perseverance rover has discovered a rock on Mars that contains what scientists believe may be signs of ancient life. The rock, dubbed “Cheyava Falls” by the rover’s science team, exhibits intriguing characteristics that suggest it may have hosted life billions of years ago. Analysis conducted by Perseverance’s onboard instruments indicates that a core sample contains chemical signatures and structures potentially formed by life when the area was rich with flowing water. While these features could indicate ancient microbial life, alternative explanations are still being considered, and further research is essential to confirm this hypothesis. The rock, which is the rover’s 22nd rock core sample, was collected on 21 July as the rover navigated the northern edge of Neretva Vallis. This ancient river valley, measuring a quarter-mile wide, was once carved by water flowing into Jezero Crater. Nicola Fox, associate administrator of the Science Mission Directorate at NASA Headquarters, remarked on the significance of the find: “This trip through the Neretva Vallis riverbed paid off as we found something we’ve never seen before, which will give our scientists so much to study.” Ken Farley, Perseverance project scientist at Caltech, highlighted the rock's potential importance: “Cheyava Falls is the most puzzling, complex, and potentially important rock yet investigated by Perseverance. We have our first compelling detection of organic material and evidence that water once passed through the rock. However, we still need to determine exactly how the rock formed.” Named after a Grand Canyon waterfall, Cheyava Falls measures 3.2 feet by 2 feet. The rock’s white calcium sulfate veins and reddish bands suggest the presence of hematite, a mineral that contributes to Mars’s distinctive rusty hue. Closer inspection revealed millimeter-sized off-white splotches surrounded by black material, akin to leopard spots. These black halos contain both iron and phosphate, as determined by the rover’s PIXL (Planetary Instrument for X-ray Lithochemistry) instrument. David Flannery, an astrobiologist from Queensland University of Technology and a member of the Perseverance science team, explained, “On Earth, these types of features in rocks are often associated with the fossilized record of microbes living in the subsurface.” As NASA continues to explore Mars, Cheyava Falls represents a significant step in the search for ancient life on the Red Planet. Further analysis and research will be required to unravel the mysteries held within this intriguing rock. Where: United States When: 25 Jul 2024 Credit: NASA/JPL-Caltech/MSSS/Cover Images **EDITORIAL USE ONLY. MATERIALS ONLY TO BE USED IN CONJUNCTION WITH EDITORIAL STORY. THE USE OF THESE MATERIALS FOR ADVERTISING, MARKETING OR ANY OTHER COMMERCIAL PURPOSE IS STRICTLY PROHIBITED. MATERIAL COPYRIGHT REMAINS WITH STATED SUPPLIER.**