The largest comet ever detected has been confirmed by astronomers using NASA’s Hubble Telescope, and it will pass by our sun in the next decade.
A comet differs from an asteroid in that an asteroid is a stony object, whereas a comet is a ball of ice and dust. Comets are also recognized for the “tail” they leave behind, as well as the blazing head, or nucleus, that appears as the comet approaches the sun.
The size of “the largest ice comet nucleus ever seen” has now been determined by astronomers. Comet C/2014 UN271, also known as Comet Bernardinelli-Bernstein, is approximately 80 miles wide, making it larger than Rhode Island. Its nucleus is predicted to weigh 500 trillion tons, which is 100,000 times heavier than the majority of comets.
In addition, the comet is moving at 22,000 mph and is getting closer to Earth. When it makes its closest approach to the sun in 2031, it will be around 1 billion miles away from the sun, somewhat farther than the distance between Earth and Saturn. The findings of the comet were published in the journal The Astrophysical Journal Letters on Tuesday.
“This comet is literally the tip of the iceberg for many thousands of comets that are too faint to see in the more distant parts of the solar system. We’ve always suspected this comet had to be big because it is so bright at such a large distance. Now we confirm it is.”
David Jewitt, planetary science and astronomy professor at UCLA and co-author of the study, said in a statement.
“This comet is essentially the tip of the iceberg for many thousands of other comets that are too faint to view in the more distant portions of the solar system,” said David Jewitt, planetary science and astronomy professor at UCLA and study co-author. Because it is so bright at such a great distance, we have always assumed that this comet must be quite massive. We can now affirm that it is. “
The comet was detected in archive photographs by astronomers Pedro Bernardinelli and Gary Bernstein in 2014, when it was more than 3 billion miles from the sun, indicating its size.
“We believed the comet might be fairly massive, but we required the best data to confirm this,” said Man-To Hui, main author of the study and professor at Macau University of Science and Technology in Taipa, Macau.
On Jan. 8, astronomers used the Hubble telescope to take photographs of the comet to confirm its size. The difficulty in understanding the photos was identifying the nucleus of the comet from the cloud and tail (or coma) that surrounded it. The coma of a comet expands as it approaches closer to the sun.
The comet is around 2 billion miles from the sun, where temperatures are predicted to be minus 348 degrees Fahrenheit, but high enough for carbon monoxide to sublimate off the comet’s surface and produce the coma.
Hui and colleagues then created a computer model of the comet and tweaked it to match the photos from the telescope. They were then able to remove the coma, leaving only the nucleus.
Hui and his colleagues then created a computer model of the surrounding coma, which they tweaked to fit the Hubble photos. The coma’s luminescence was then removed.
The scientists next took photographs of the nucleus and compared their brightness to radio measurements from Chile’s Atacama Large Millimeter/submillimeter Array (ALMA). Astronomers were able to establish its diameter as well as the appearance of the nucleus using the combined data.
“It’s huge and blacker than coal,” Jewitt remarked.
The comet orbits the solar system every 3 million years and travels as far as half a light-year from the sun.
Astronomers anticipate the comet will shed light on what Oort Cloud comets are like. The Oort Cloud is thought to be a gigantic nesting ground for trillions of comets, but it has yet to be directly detected.
