Big or really really big? Chinese scientists measure the largest comet, coming from the edge of the solar system
- Images of C/2014 UN271 – a comet 128km in diameter and completing an orbit of the sun every few million years – were captured by the Hubble Space Telescope
- The exact size of a comet’s nucleus is difficult to establish because of its distance from Earth and the cloud called ‘coma’ surrounding it, astronomer says
At about 128km (80 miles) across, it’s about 50 times bigger than any other and could have a mass of as much as 500 trillion tonnes.
When the comet was first discovered from archived observation data in June 2021, “it caught our attention immediately”, said Man-To Hui of the Macau University of Science and Technology, Taipa Macau, who is lead author of a paper published in Astrophysical Journal Letters last week.
“Comets are believed to be the most pristine objects in our solar system and still have abundant information regarding the earliest history and evolution of our solar system,” he said.
The colossal comet – C/2014 UN271 or Bernardinelli-Bernstein – is believed to have arrived from a bubblelike, dark, icy region called the Oort Cloud at the edge of our solar system. It follows a highly elongated path and completes one orbit of the sun every few million years.