Comet 2I/Borisov, only the second interstellar object ever spotted in our solar system, is racing through our celestial neighborhood at the “breathtaking” speed of 110,000 mph.
As it zoomed close to our sun earlier this week, the Hubble Space Telescope snapped a shot of the comet, which is an ancient ball of ice, rock and dust that formed in a distant star system.
Scientists are “clamoring” to study this frozen time capsule, NASA said, looking for clues as to what may lie beyond our solar system.
“Data from the Hubble Space Telescope give us the best measure of the size of comet 2I/Borisov’s nucleus, which is the really important part of the comet,” said David Jewitt, a UCLA professor of planetary science and astronomy who analyzed and interpreted data from the new image.
“Surprisingly, our Hubble images show that its nucleus is more than 15 times smaller than earlier investigations suggested it might be, Jewitt said, adding that its diameter is only about 6/10 of a mile.
He said that knowing the size is potentially useful for beginning to estimate how common such objects may be in the solar system and our galaxy.
The comet will make its closest approach to Earth in late December at a distance of 180 million miles. By mid-2020, it will zoom past Jupiter on its way back into interstellar space, where it will drift for billions of years.
The comet was discovered Aug. 30 by Gennady Borisov at an observatory in Nauchnij, Crimea.
NASA said that 2I/Borisov may represent only the beginning of a series of discoveries of interstellar objects paying a brief visit to our solar system. There may be thousands of such interstellar objects here at any given time; most, however, are too faint to be detected with present-day telescopes.
2I/Borisov is only the second known interstellar visitor to swoop through our backyard. Two years ago, a cigar-shaped rock, ‘Oumuamua,’ paid a brief visit to our solar system.