NASA’s Hubble Telescope has accurately measured the size of the largest comet ever observed so far. The comet nicknamed Bernardinelli-Bernstein will pass close to the Sun over the next decade.
Discovered for the first time in 2014, comet C / 2014 UN271 or Bernardinelli-Bernstein was quickly called the largest comet ever observed. Last year, two Pennsylvania astronomers estimated its diameter to be between 100 and 200 kilometers. Astronomers finally got an accurate measurement of its size thanks to the NASA Hubble Telescope. Their study has just been published in The Astrophysical Journal Letters.
According to observations from the Hubble telescope, comet Bernardinelli-Bernstein is about 129 kilometers wide. Its core weighs about 500 trillion tons, nearly 100,000 times more than the majority of comets. And yes, C/2014 UN271 deserves its nickname of “ largest icy comet core ever seen ».
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The gigantic 129 kilometer wide comet will pass closest to the Sun in 2031
In their study, the scientists explain that the Hubble telescope captured five consecutive images lasting 285 seconds during his observation of the comet. ” The telescope tracked the non-sidereal motion of the comet, resulting in trailing background sources, despite the comet’s great distance “, detail the astronomers. They had to create computer models of the comet to distinguish its nucleus from its “hair”. This one is the nebulous envelope formed around the nucleus of a comet when it heats up as it passes near the Sun.
Comet Bernardinelli-Bernstein is heading towards our star over 35,405 km / h. It will pass close to the Sun over the next decade, but pose no danger to us. In fact, it will be around 1.6 billion kilometers from the Sun when she’s at the closest point in 2031. This distance is greater than the distance between Earth and Saturn.
Finally, the discovery of this comet bears witness to the gigantic size of other comets at the edge of space. As David Jewitt, professor of planetary sciences and astronomy and author of the study, explained, “ this comet is literally the tip of the iceberg for several thousand comets that are too faint to be seen in the most distant parts of the solar system ».
Source : Phys.org