According to a recent study released on the preprint site arXiv.org, a massive comet — potentially the biggest ever observed — is barreling toward the inner solar system, with an estimated arrival time of 10 years from now.
The Bernardinelli-Bernstein comet (also known as C/2014 UN271) is at least 62 miles (100 kilometers) wide, making it 1,000 times more large than a regular comet. According to a statement announcing the comet’s discovery in June 2021, it is so big that astronomers mistook it for a dwarf planet.
However, a deeper examination of the object revealed that it was speeding through the Oort cloud, a huge scrapyard of ice boulders with billions of them. The object looked to be heading our way, with a luminous tail, or “coma,” behind it, indicating that it was an ice comet approaching the relatively warm inner solar system.
Researchers have now researched the big comet in greater depth, and they have revised their predictions for its path toward the sun.
To begin with, the massive asteroid presents no threat to Earth. Bernardinelli-Bernstein (BB) is now traveling through the Oort cloud at a distance of roughly 29 times the Earth-Sun distance, or 29 astronomical units (AU). According to the researchers, the comet’s closest approach to Earth will take place in the year 2031, when it will swoop within 10.97 AU of the sun, putting it just outside of Saturn’s orbit.
While the comet will be too far away for humans to observe without telescopes, it will be far closer than the rock’s last visit to our area of the solar system. The study’s authors determined that comet BB made its closest approach to the solar 3.5 million years ago, reaching within 18 AU of the sun.
According to the experts, the comet has gone as far as 40,000 AU away, deep into the enigmatic Oort cloud.
“We infer that BB is a ‘new’ comet in the sense that no evidence for [a] prior encounter closer than 18 AU,” the researchers stated in their paper, implying that humans have never seen it previously.
The Dark Energy Survey (DES) – research to explore the expansion of the cosmos that spanned from August 2013 to January 2019 — is responsible for our present picture of the big, distant comet. Astronomers discovered more than 800 previously undiscovered objects beyond Neptune’s orbit during the study, which scanned 300 million galaxies in the southern sky. One of these objects was the Bernardinelli-Bernstein comet.
Over the following decade, researchers will have plenty of opportunities to observe the huge comet as it approaches Earth. Because comets from deep in the Oort cloud are expected to stay essentially unaltered since they were kicked away from the sun billions of years ago, getting a closer look at the rock might help scientists learn more about the chemical makeup of the early solar system. It’ll be a once-in-a-lifetime brush with the early solar system, with millions of years separating the comet’s next to near encounter from the one after that.
