NASA's Curiosity rover discovers organic molecules on Mars that could be chemical building blocks of life preserved for 3.5 billion years.

NASA's Curiosity rover detected organic molecules on Mars, including chemicals widely considered building blocks of life that scientists believe have been preserved for 3.5 billion years.

Scientists cannot yet determine if the organic molecules discovered on Mars represent actual life or just chemical precursors, leaving the question of Martian life still unanswered.