This is a big one.
A giant comet – which scientists say is arguably the largest comet discovered in modern times – is on its way toward the sun and will make its closest approach to Earth in 2031.
"We have the privilege of having discovered perhaps the largest comet ever seen – or at least larger than any well-studied one – and caught it early enough for people to watch it evolve as it approaches and warms up," said University of Pennsylvania astronomer Gary Bernstein, a co-discoverer of the object.
It is the most distant comet to be discovered on its incoming path, giving us years to watch it evolve as it approaches the sun, the National Science Foundation said.
The comet is also an infrequent visitor to our neck of the woods: "It has not visited the solar system in more than 3 million years," Bernstein said in a statement.
The comet, which is estimated to be 60 to 120 miles across, or about 10 times the diameter of most comets, is an icy relic flung out of the solar system by the migrating giant planets in the early history of the solar system.
This comet is quite unlike any other seen before, the National Science Foundation said, and the huge size estimate is based on how much sunlight it reflects.
At its current pace, the comet will travel from its current point just past Neptune’s orbit to nearly reach Saturn’s orbit in 2031, Smithsonian magazine said.
The object probably will only be about as bright as Pluto’s moon Charon at that point, according to New Atlas, so people here on Earth will likely need to rely on telescopes to capture photographs of it. Then it will head back into distant space from where it came.
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The comet probably came from the Oort Cloud, which is believed to be a giant spherical shell that surrounds the solar system, according to NASA. Most long-period comets such as this one come from the Oort Cloud, NASA said.
It could be the largest object from the Oort Cloud ever detected, and it is the first comet on an incoming path to be detected so far away.
Astronomers suspect that there may be many more undiscovered comets of this size waiting in the Oort Cloud. These giant comets are thought to have been scattered to the far reaches of the solar system by the migration of Jupiter, Saturn, Uranus and Neptune early in their history.
The comet is dubbed Bernardinelli-Bernstein after the two astronomers who discovered it: Pedro Bernardinelli (also from the University of Pennsylvania) and Gary Bernstein. Its official name is 2014 UN271.
This article originally appeared on USA TODAY: Comet Bernardinelli-Bernstein is largest ever seen, heading to sun