2. Learn about rocks on Mars
Scientists are still learning about the igneous, sedimentary, and metamorphic rocks on Mars. Sedimentary rocks can give us a glimpse into the history of Mars if we are able to analyze the layers and the materials inside the rock. Because humans haven’t yet been to Mars, we rely on robots, like Mars rovers, to explore and report back on their findings.
Scientists are especially interested in a type of sedimentary rock called a conglomerate. These rocks are made up of small pebbles of other rock types cemented together. Conglomerates are interesting to scientists because the rounding of the pebbles indicates that water once eroded, or ate away at, these rocks. And where there was once water, there might have once been life. (Scientific evidence indicates that life forms, if they existed on Mars in the past, would likely have been microscopic.)
NASA’s Perseverance rover is specially designed to investigate rocks like conglomerates as part of its mission to seek signs of ancient microbial life and collect rock and soil samples for possible return to Earth.
About the image:
The image above, captured by NASA's Curiosity rover on Mars, shows an outcropping – an area where ancient bedrock underneath the surface is exposed. Outcroppings on Earth are known to form as a result of running water and create gravel that's a similar size and shape. By comparing this image of Mars to similar features on Earth, geologists have been able to theorize that Mars might have also once had running water. › Full image and caption