Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have detected the faint molecular fingerprint of methyl chloride – a chemical commonly produced by industrial and biological processes here on Earth – around an infant star system known as IRAS 16293-2422. Traces of this organic compound were also discovered in the thin atmosphere of comet 67P/Churyumov-Gerasimenko (67P/C-G) by the Rosetta space probe.