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NASA Confirms It Has Found The Largest Comet Ever Sighted In The Solar System

NASA's Hubble Space Telescope has found the largest icy comet nucleus ever seen by astronomers.

According to NASA, the comet is 129 kilometres across, and its nucleus is about 50 times larger than most-known comets.

It is estimated to weigh an incredible 500 trillion tons.

Named C/2014 UN271 (Bernardinelli-Bernstein), NASA said it is "barrelling this way" from the edge of the solar system towards us.

But don't panic! It won't get closer than 1.6 billion kilometres to the Sun, or roughly the same distance away as Saturn.

"This comet is literally the tip of the iceberg for many thousands of comets that are too faint to see in the more distant parts of the solar system," said David Jewitt, a professor of planetary science and astronomy at the University of California, Los Angeles (UCLA) and co-author of the new study in The Astrophysical Journal Letters.

" We've always suspected this comet had to be big because it is so bright at such a large distance. Now we confirm it is."

Comet C/2014 UN271 was first observed in November 2010, from archival images from the Dark Energy Survey at the Cerro Tololo Inter-American Observatory in Chile.

New research into the comet saw the Hubble Telescope take five photos of it on January 8, 2022.

Because it is still so far away, the research team used a computer model to compare the brightness of the comet's nucleus to other known ones.

"This is an amazing object, given how active it is when it's still so far from the Sun," said the research paper lead author Man-To Hui of the Macau University of Science and Technology, Taipa, Macau.

"We guessed the comet might be pretty big, but we needed the best data to confirm this."