Back in 2019, a team of astronomers from NASA and the ESA, together with a team from the International Scientific Optical Network (ISON), made an announcement: they found the comet 2I/Borisov. This comet is the second interstellar visitor which was observed to pass through our Solar System. This is the reason why astronomers from everywhere have watch this comment on its way towards the Sun.
From NASA’s Goddard Space Flight Center, a group led by Martin Cordiner and Stefanie Milam observed 2I/Borisov by making the most out of ALMA (ESO’s Atacama Large Millimeter/submillimeter Array). This thing helped astronomers to observe the gases that the comet released, as it found its way to the Sun. The comet gave us information about the first-ever chemical composition readings of an interstellar object. Of course, everyone is interested in the study of comets, because they represent some material left from the formation of the Solar System. They also spend most of their time in very cold environments. Most of the comets which were observed in our solar system came from the Kuiper Belt or the Oort Cloud.
Also, the interior of comets hasn’t changed since the formation of the Solar System, so by studying their interiors, we can understand more about the processes that took place during their birth. The study is possible when comets draw closer to their suns, and when their ices begin to sublimate, which is a process that we know as outgassing.
Interstellar comets are very popular with the astronomers because they can help us better understand the formation and evolution of star systems, of course, other than our Solar System. So when they observed this comet, they detected two types of gas molecules coming from the it: hydrogen cyanide (CHN) and carbon monoxide (CO).
Stefanie Milam stated: “The comet must have formed from material very rich in CO ice, which is only present at the lowest temperatures found in space, below -420 degrees Fahrenheit (-250 degrees Celsius).”