NASA’s Mars rover Perseverance has uncovered rocks in a dry river channel that may hold potential signs of ancient microscopic life. Scientists reported the findings Wednesday, but stressed that in-depth analysis is needed of the sample gathered there last summer before reaching any conclusions. Roaming Mars since 2021, the rover cannot directly detect life. Instead, it carries a drill to penetrate rocks and tubes to hold the samples gathered from places judged most suitable for hosting microscopic life billions of years ago. The samples are awaiting retrieval.