Subj : Daily APOD Report To : All From : Alan Ianson Date : Sun Sep 28 2025 00:14:26 Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2025 September 28 Part of a large rock on Mars is shown being mostly orange. On the rock are several irregular light-colored areas surrounded by a dark border. The spots are only millimeters across but might be a remnant biosignature of ancient Martian life. Please see the explanation for more detailed information. Leopard Spots on Martian Rocks Image Credit: NASA, JPL-Caltech, MSSS, Perseverance Rover Explanation: What is creating these unusual spots? Light-colored spots on Martian rocks, each surrounded by a dark border, were discovered last year by NASA's Perseverance Rover currently exploring Mars. Dubbed leopard spots because of their seemingly similarity to markings on famous Earth-bound predators, these curious patterns are being studied with the possibility they were created by ancient Martian life. The pictured spots measure only millimeters across and were discovered on a larger rock named Cheyava Falls. The exciting but unproven speculation is that long ago, microbes generated energy with chemical reactions that turned rock from red to white while leaving a dark biosignature ring, like some similarly appearing spots on Earth rocks. Although other non-biological explanations have not been ruled out, speculation focusing on this potential biological origin is causing much intrigue. Tomorrow's picture: comet comet __________________________________________________________________ Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) NASA Official: Amber Straughn Specific rights apply. NASA Web Privacy, Accessibility, Notices; A service of: ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. --- BBBS/Li6 v4.10 Toy-7 * Origin: The Rusty MailBox - Penticton, BC Canada (1:153/757) .