Scientists may have discovered signs of ancient life on Mars. NASA’s Perseverance rover recently sampled a rock with markings that looked like poppy seeds and leopard spots. The markings contain minerals produced by chemical reactions that could be associated with microbes, experts say. (Microbes are living things that can be seen only with a microscope, like bacteria and certain fungi.) These minerals can also be produced without microbes, but scientists say that would likely have required extremely high temperatures or acidic conditions, and the sample doesn’t show any evidence of that being the case. The rock was found near what was once a river, and the area is rich in chemical compounds that could have supported life. To learn more, researchers will need to bring the sample to Earth for further study. For now, though, many are excited about the discovery. Says Sean Duffy, the acting administrator of NASA: “This very well could be the clearest sign of life that we’ve ever found on Mars.”