Researchers have discovered that the composition of comet 2I/Borisov’s is surprisingly different from comets hailing from our celestial neighbourhood. The study suggests that the comet has travelled from a very cold place - as cold as the area where Pluto is in relation to Sun, called the Kuiper Belt. Astronomers, who used NASA’s Hubble Space Telescope and the National Radio Astronomy Observatory’s Atacama Large Millimeter/submillimeter Array, found that the comet’s carbon monoxide concentration is higher than that of the average solar system comet.
“With an interstellar comet passing through our own solar system, it’s like we get a sample of a planet orbiting another star showing up in our own backyard,” said John Noonan, a member of the Hubble research team, in a statement.
The team, led by Dennis Bodewits of Auburn University in Alabama, used Hubble's unique ultraviolet sensitivity to spectroscopically detect carbon monoxide gas escaping from comet Borisov's solid comet nucleus. They were surprised to find that Borisov’s coma contained a high amount of carbon monoxide gas, at least 50% more abundant than water vapour. They additionally theorize that 2I/Borisov may have originated around the most common type of star in the Milky Way: a red dwarf, which are much smaller and dimmer than the Sun.
“The amount of carbon monoxide did not drop as expected as the comet receded from the Sun. This means that we are seeing the primitive layers of the comet, which really reflect what this object is made of,” Bodewits said in a statement.
The lead researcher opined that the comet might have come from a much colder place and from a very different debris disk around a star than our own because of the abundance of carbon monoxide ice that survived so close to the Sun. According to the study published in Nature Astronomy, the amount of carbon monoxide is more than three times higher than the previously measured quantity for any comet entering the inner solar system.
(Image: Twitter / @ULiegeRecherche)