Interstellar comet Borisov

23 Apr 2020

At https://phys.org/news/2020-04-alma-reveals-unusual-composition-interstel... ... ALMA, the Atacama Large Millimeter/submillimeter Array, has disovered some unusual things about interstellar Comet Borisov, late last year (December 2019). They observed the  chemicals stored inside the comet that is thought to have originated in another solar system. See https://doi.org/10.1038/s41550-020-1087-2 ... and https://doi.org/10.1038/s41550-020-1095-2 ... where it seems ALMA detected two molecules in the gas ejected from the comet - hydrogen cyanide and carbon monoxide. Whereas the hydrogen cyanide was not different to that seen in solar  system comets it is thought the amount of carbon monoxide was anomalous - much higher levels than found in solar system comets. This is thought, in turn, to show the comet formed in another solar system, far away. However, it should be born in mind that carbon monoxide is one of the most common molecules in space, but concentrations differ widely (in different comets). 

At https://phys.org/news/2020-04-interstellar-comet-2iborisov-carbon-monoxi... ... is another post on the same subject. It provides more details on how the data was collected and analysed. It also infers that some solar system comets have an abnormally high carbon monoxide content (not too different from Borisov). However, the vast majority of comets have a lesser amount of carbon monoxide.