Free Astronomy Magazine November-December 2017

38 NOVEMBER-DECEMBER 2017 SPACE CHRONICLES ALMA and Rosetta detect Freon-40 in space by ESO U sing data captured by ALMA in Chile and from the ROSINA instrument on ESA’s Rosetta mission, a team of astronomers has found faint traces of the chemical compound Freon-40 (CH 3 Cl), also known as methyl chloride and chloromethane, around both the infant star system IRAS 16293-2422, about 400 light-years away, and the famous comet 67P/Churyumov- Gerasimenko (67P/C-G) in our own Solar System. The new ALMA obser- vation is the first detection ever of a stable organohalogen in interstel- lar space. Organohalogens consist of halo- gens, such as chlorine and fluorine, bonded with carbon and sometimes other elements. On Earth, these compounds are created by some bi- ological processes — in organisms ranging from humans to fungi — as well as by industrial processes such as the production of dyes and medi- cal drugs. This new discovery of one of these compounds, Freon-40, in places that must predate the origin of life, can be seen as a disappointment, as ear- lier research had suggested that these molecules could indicate the presence of life. “Finding the organohalogen Freon- 40 near these young, Sun-like stars O rganohalogen methyl chloride (Freon-40) discovered by ALMA around the in- fant stars in IRAS 16293-2422. These same organic compounds were discovered in the thin atmosphere surrounding Comet 67P/C-G by the ROSINA instrument on ESA’s Rosetta space probe. [B. Saxton (NRAO/AUI/NSF); NASA/JPL-Caltech/UCLA] was surprising,” said Edith Fayolle, a researcher with the Harvard- Smithsonian Center for Astrophysics in Cambridge, Massachusetts in the USA, and lead author of the new paper. “We simply didn’t predict its formation and were surprised to find it in such significant concentra-