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How would we know whether there is life on Earth? This bold experiment found out

Thirty years ago, astronomer Carl Sagan convinced NASA to turn a passing space probe’s instruments on Earth to look for life — with results that still reverberate today.
By
  1. Alexandra Witze
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It began the way many discoveries do — a tickling of curiosity in the back of someone’s mind. That someone was astronomer and communicator Carl Sagan. The thing doing the tickling was the trajectory of NASA’s Galileo spacecraft, which had launched in October 1989 and was the first to orbit Jupiter. The result was a paper in Nature 30 years ago this week that changed how scientists thought about looking for life on other planets.

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Nature 622, 451-452 (2023)

doi: https://doi.org/10.1038/d41586-023-03230-z

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