A gigantic comet, possibly the largest ever seen, is currently hurtling towards our solar system. The comet is so huge that astronomers initially believed it to be a dwarf planet!
The comet C/2014 UN271 nicknamed Comet Bernardinelli-Bernstein was discovered by two astronomers Pedro Berardinelli and Gary Bernstein, from the University of Pennsylvania earlier this year.
Observed just past the orbit of Neptune, at 29 astronomical units, it also sets a record for being the most distant comet to have ever been observed, mostly thanks to its brightness.
At first glance, astronomers estimated it to be around 100 kilometers in length, but on further observations, they found the comet to be longer than that. The was observed to be at least 150 kilometers in length, based on the intensity of its brightness. It is the largest comet to ever have been observed in history (for comparison, the famous Halley’s comet is only 80 kilometers in length).
The orbit of 2014 UN271. Credit: JPL Solar System Dynamics
“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 Gary Bernstein after the discovery.
Despite its size, there’s no reason to worry, as it is not expected to get any closer to the Sun than just outside Saturn’s orbit by 2031. Based on its current orbit, astronomers think the comet is making its first foray into the solar system in more than three million years.
The comet’s elliptical orbit is so long that at its farthest it is over two trillion kilometers away from the sun. According to astronomer Phil Plait, at that distance, the sun’s gravity is so weak, just a whisper could push the comet into interstellar space.
Cover Image: Illustration of Comet Bernadinelli-Berstein. (NOIRLab/NSF/AURA/J. da Silva