Mars Has the Ingredients. Nobody Knows Who Packed the Bag.
A 3.5-billion-year-old Martian rock just yielded 21 organic molecules, including a DNA precursor never seen on Mars before. So where did they come from?
The Ocean Smells Like Life. A Planet 124 Light-Years Away Does Too.
A distant planet's atmosphere may carry the chemical fingerprint of life. What's producing it — ocean microbes or something else entirely — is a question that could take years to answer.