A giant comet, probably the largest known at this time, is heading for the inner part of the solar system. At first it was even thought of as a dwarf planet.
There is no cause for concern – a comet named C / 2014 UN271 (Bernardine-Bernstein) will not approach the Sun close to Saturn’s orbit. However, its size and relative proximity offer an amazing chance to study the ancient object of the Oort cloud, which in turn will provide us with new information about the formation of the solar system.
“We have the privilege of discovering perhaps the largest comet we have ever seen, or at least the largest of any well-studied comet; “We noticed it so early that we would have time to observe its changes as it approached and as it warmed,” said Gary Bernstein, an astronomer at the University of Pennsylvania.
According to him, this comet last visited the inner part of the solar system 3 million years ago.
The outer part of the solar system is largely a mysterious place. It is very far from us, it is quite dark and the objects there are also very small; Consequently, seeing anything beyond Neptune’s orbit is a very difficult task.
What we know about this region of the cosmos
There is a general idea about the structures of this region of the cosmos – the Kuiper belt is made up of small icy objects, and beyond that is the Oort cloud, which is difficult to determine the exact composition of.
However, we are getting more and more information from a rather unexpected source: the Dark Energy Research Program (DES), which ran from August 2013 to January 2019.
He observed the southern sky in the infrared and near-infrared range for several hundred nights; Studied objects such as supernovae and galaxy clusters to calculate the rate of expansion of the universe; According to scientists, it is dark energy that affects expansion.
The depth, breadth, and accuracy of the program also proved to be quite convenient for identifying objects outside the solar system, beyond Neptune, 30 astronomical units away from the Sun (the astronomical unit is the average distance between the Sun and the Earth). In early 2021, a group of astronomers said that according to DES data, 461 hitherto unknown objects were discovered in the outer part of the solar system.
One such object was noticed by Bernstein and his colleague, astronomer Pedro Bernardini, it was Comet C / 2014 UN271, called the Bernardin-Bernstein. This time, together with colleagues, they described this comet in detail in a publication received by The Astrophysical Journal Letters.
“We conclude that C / 2014 UN271 (Bernardine-Bernstein) is a ‘new’ comet in the sense that we have no evidence that it has come close to 18 astronomical units from the Oort cloud to the Sun so far,” the researchers wrote.
They say it may be the oldest comet ever discovered.
“Besides, we observed it before it entered the uranium orbit, and it may not have come so close to the previous orbit,” the researchers said.
According to the group’s analysis, C / 2014 UN271 (Bernardine-Bernstein) began its inward travel at a distance of about 44,400 astronomical units from the Sun. It is already the Oort cloud area, a vast expanse of icy objects that stretches from 2,000 astronomical units to 100,000 astronomical units from the Sun.
At the time of its discovery, the comet was about 29 astronomical units away from the Sun. It will come closest to the Sun in 2031, at a distance of about 10.97 astronomical units; For comparison, Saturn’s orbit is 9.5 astronomical units away from the Sun on average.
Comet C / 2014 UN271 (Bernardine-Bernstein) is 155 kilometers wide, or quite large, but still does not appear to the naked eye.
However, scientists will use every opportunity to study it with telescopes. They hope that a better understanding of its composition will tell us much about the early solar system and its distant approaches.
Because it is believed that icebergs so far from our planetary system are more or less unchanged from the day they formed, that is, for the entire 4.5 billion years. Consequently, volatiles embedded in comet ice may contain information about the chemical composition of the outer part of the solar system during formation.
Scientists have already noticed signs of coma – the cometic atmosphere that occurs when a comet comes close to the sun. The increase in heat evaporates (sublimation) the ice on the comet’s surface and produces a visible coma, even coming from a closer distance to the comet’s tail. Spectral analyzes of these formations tell us a great deal about the comet’s entrails.
Since we know very little about the Oort cloud and its objects, Comet C / 2014 UN271 (Bernardine-Bernstein) is a very rare opportunity to explore this mysterious place of our homeland in space.
Prepared according to ScienceAlert.