Free Astronomy Magazine July-August 2020

16 JULY-AUGUST 2020 SPACE CHRONICLES by Martin Cordiner and Stefanie Milam at NASA’s Goddard Space Flight Center in Greenbelt, Mary- land, revealed that the gas coming out of the comet contained un- usually high amounts of carbon monoxide (CO). The concentration of CO is higher than anyone has de- tected in any comet within 2 astro- nomical units (au) from the Sun, that is, within less than 186 million miles, or 300 million kilometers. 2I/Borisov’s CO concentration was estimated to be between nine and 26 times higher than that of the av- erage solar system comet. Astronomers are interested to learn more about comets, because these objects spend most of their time at large distances from any star in very cold environments. Unlike planets, their interior compositions have not changed significantly since they were born. Therefore, they could reveal much about the processes that occurred during their birth in protoplanetary disks. “This is the first time we’ve ever looked inside ALMA reveals unusual composition of interstellar comet 2I /Borisov A galactic visitor entered our solar system last year – inter- stellar comet 2I/Borisov. When astronomers pointed the Atacama Large Millimeter/submillimeter Array (ALMA) toward the comet on 15 and 16 December 2019, for the first time they directly observed the chemicals stored inside an object from a plan- etary system other than our own. This research is published online in the journal Nature Astronomy . The ALMA observations from a team of international scientists led by ALMAObservatory