Free Astronomy Magazine July-August 2015

SPACE CHRONICLES Complex organic molecules discovered in infant star system by ESO N ew ALMA observations reveal that the protoplanetary disc surrounding the young star MWC 480 contains large amounts of methyl cyanide (CH3CN), a com- plex carbon-based molecule. There is enough methyl cyanide around MWC 480 to fill all of Earth’s oceans. This star is only about one million years old. By comparison the Sun is more than four billion years old. The name MWC 480 refers to the Mount Wilson Catalog of B and A stars with bright hydrogen lines in their spec- tra. Both this molecule and its sim- pler cousin hydrogen cyanide (HCN) were found in the cold outer reaches of the star’s newly formed disc, in a region that astronomers believe is analogous to the Kuiper Belt — the realm of icy planetesimals and com- ets in our own Solar System beyond Neptune. Comets retain a pristine re- cord of the early chemistry of the Solar System, from the period of planet formation. Comets and as- teroids from the outer Solar System are thought to have seeded the young Earth with water and organic molecules, helping set the stage for the development of primordial life. “Studies of comets and asteroids show that the solar nebula that spawned the Sun and planets was rich in water and complex organic compounds,” noted Karin Öberg, an A rtist impression of the protoplanetary disc surrounding the young star MWC 480. ALMA has detected the complex organic molecule methyl cya- nide in the outer reaches of the disc in the region where comets are believed to form. This is another indication that complex organic chemistry, and poten- tially the conditions necessary for life, is universal. [B. Saxton (NRAO/AUI/NSF)]