That's all. It looks like this is really the end of the road for 2I / Borisov, a comet that flew many light years in space before entering the solar system.
New data show the comet is falling apart.
According to the latest observations of the comet with the Hubble telescope, the comet split into at least two parts.
'Images from March 23, 2020 show a single inner bright core, similar to that seen in all previous HST 2I / Borisov images,' wrote a team of astronomers led by David Jewitt of the University of California, Los Angeles.
'In contrast, images from March 30, 2020 show a clearly non-stellar core, consistent with two unresolved components 0.1 arc second apart (180 km from the comet) and aligned with the major axis of the larger dust coma.'
This is not an unexpected turn of events. Astronomers watch the comet closely after its closest approach to the Sun or perihelion on December 8, 2019.
It is quite normal for comets to decay when they reach perihelion. What we think is due to the sublimation of cometary ices when they are heated by the Sun. This is believed to spin the comet's nucleus, causing its fragmentation during centripetal instability.
A team of Polish astronomers led by Michal Dragus and Piotr Guzik of the Jagiellonian University noticed that in early March the comet cleared up significantly, twice in a few days. This behavior, they said, “clearly indicates ongoing fragmentation of the nucleus.”
This process may sound like sad news for comet 2I / Borisov, but it is an amazing opportunity for astronomers. As the comet fragments further, we can photograph its spectrum to find out what it is made of and how similar or different it is to comets in the solar system.
Observations so far have shown that the comet's color and composition are, in fact, very similar to comets from the outer solar system. This is exciting because it is believed that the comets of the solar system could carry a bunch of ingredients for the birth of life on Earth. If 2I / Borisov looks like these comets, it hints that comets could carry such ingredients to other worlds.
Sources: Photo: (NASA / ESA / D. Jewitt)
