A martian rock has lots of carbon on it, and it's not clear why

Biology could explain the find, but there are other potential explanations. https://arstechnica.com/science/2026/07/a-martian-rock-has-lots-of-carbon-on-it-and-its-not-clear-why/?utm_brand=arstechnica&utm_social-type=owned&utm_source=mastodon&utm_medium=social