Astronomers have measured the icy core of one of the largest comets ever discovered – a 4-billion-year-old giant rock currently heading toward Land at 22,000 mph (35,000 km/h).
Don’t worry: The massive icy rock — named C/2014 UN271, or Bernardinelli-Bernstein (BB) after its discoverers — is on track to miss our planet by about a billion miles as it approaches its closest point in 2031, Live Science previously reported. For comparison, this is greater than the average distance between Saturn and the sun – And far enough away that stargazers wouldn’t be able to see the BB’s flight with the naked eye.
However, as BB gets ever closer, astronomers are taking the opportunity to study it in more detail. Previous research showed that the icy space rock is more than 80 miles (128 km) wide — about twice the width of Rhode Island — and about 100,000 times larger than a typical comet. BB is so large that it was once mistaken for a dwarf planet; Recent observations have shown the rock to have a glowing tail, or coma, which is a clear indication of an icy comet rising through the relatively warm interior. Solar System.
Now, astronomers have used the Hubble Space Telescope to look at the scorching rock coma and focus directly on its icy core. While the BB is still a long way from imaging in clear detail, Hubble’s observations allowed the researchers to pinpoint a bright spot of light that corresponds to the comet’s core, or nucleus, according to research published April 12 in . Astrophysical Journal Letters.
The team then used a computer model to digitally remove the comet’s bright coma’s glow, leaving only the nucleus behind. The resulting data shows that the comet’s nucleus is about 50 times larger than typical comets observed in the inner solar system – the largest nucleus ever discovered by astronomers.
The team’s analysis also revealed the color of the comet’s icy core.
“It’s big and it’s blacker than coal,” said study co-author David Jewett, a professor of planetary sciences at the University of California, Berkeley. He said in a statement.
BB is still about 2 billion miles (3.2 billion km) from Earth, and has a large area to cover before approximating in 2031. Researchers report in a study published in November 2021 in Astrophysical Journal Letters The comet made its last approach to Earth 3.5 million years ago, when it approached the Sun about 1.6 billion miles (2.6 billion km).
Meanwhile, BB has been swooping through the Oort Cloud – a vast junkyard of icy rock that surrounds our solar system, potentially extending billions of miles into space.
Originally published on Live Science.