- “This is the first time we’ve ever looked inside a comet from outside our solar system.”
- The comet is rich in the poisonous gas carbon monoxide.
- The comet is likely no more than 3,200 feet across, about the length of nine football fields.
It’s a weird visitor from outer space, scientists announced Monday.
Astronomers say that interstellar visitor 2I/Borisov is in some ways very different from comets that come from our own solar system. Close study of the comet, which is now zooming through our solar system, is also revealing insights into how other star systems might have formed, according to new scientific studies published Monday.
“This is the first time we’ve ever looked inside a comet from outside our solar system,” said astrochemist and study lead author Martin Cordiner from NASA’s Goddard Space Flight Center, in a statement, “and it is dramatically different from most other comets we’ve seen before.”
Two studies were published Monday about the comet in the peer-reviewed British journal Nature Astronomy.
The comet is rich in the poisonous gas carbon monoxide, which is common in space but usually not in comets, according to the new research.
“The comet must have formed from material very rich in carbon monoxide ice, which is only present at the lowest temperatures found in space, below –420 degrees Fahrenheit,” said planetary scientist and study co-author Stefanie Milam, also from NASA Goddard.
“We like to refer to 2I/Borisov as a snowman from a dark and cold place,” said planetary scientist Dennis Bodewits of Auburn University in Alabama, lead author of the other study, according to Reuters.
“Comets are left-over building blocks from the time of planet formation,” he said. “For the first time, we have been able to measure the chemical composition of such a building block from another planetary system while it flew through our own solar system,” Bodewits added to Reuters.
Following the ejection of 2I/Borisov from its original environment, the cold temperatures of interstellar space would have preserved its chemical make-up for millions or even billions of years until it reached our solar system.
Comet 2I/Borisov was spotted on Aug. 30, 2019, by comet hunter Gennady Borisov in Crimea. The vagabond comet resembles other solar system comets, but astronomers determined its interstellar origins based on its orbital path.
Since its discovery, a slew of telescopes, including the Hubble Space Telescope, have observed the comet as it traveled through the solar system and swung past the sun. It will eventually leave the solar system and continue its journey through space.
The comet consists of a loose agglomeration of ices and dust particles, and is likely no more than 3,200 feet across, about the length of nine football fields.
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. In 2017, a cigar-shaped rock, ‘Oumuamua,’ paid a brief visit to our solar system.