Posted17 avril 2022, 22:35
Thanks to the Hubble telescope, NASA has just confirmed the imposing size of the largest comet ever detected in space. It would approach our planet.
The comet C/2002 VQ94 (Linear), with its 90 kilometers in diameter, was until now the largest ever discovered. Today, thanks to observations made with the Hubble telescope, comet 2014 UN271 – also called Bernardinelli-Bernstein after its first observers – has dethroned it.
This comet was discovered in 2014, but then too far from us, its exact size could not be determined. Observations made with the Hubble Space Telescope have recently made it possible to estimate it.
This star is about 130 kilometers in diameter, a core about 50 times larger than that of most known comets. Its weight is just as impressive, NASA speaking of 500 billion tons.
“Tip of the Iceberg”
“This comet is literally the tip of the iceberg of several thousand comets that are too faint to be seen in the most distant parts of the solar system. We always suspected that this comet must be big because it is so bright at such a great distance. Now we confirm that is the case,” said David Jewitt, professor of planetary science and astronomy at the University of California and co-author of the study published in «The Astrophysical Journal Letters».
At Saturn’s orbit
It is certainly a gigantic celestial object, whose current trajectory directs it towards our planet at 35,000 km/h. – a speed which is not so extraordinary in the interstellar vacuum, the International Space Station, for example, moving at more than 28,000 km/h.
But the comet should not pass too close to our planet, nor immediately. Indeed, according to the scientists, “the comet will not approach within a billion kilometers of the Sun, and that will not happen until 2031”. In January 2031, it would therefore be on the outskirts of Saturn’s orbit. Once past, it should resume its journey to the “icy confines” of the Solar System.
Oort Cloud
According to the authors of the research, Bernardinelli-Bernstein has already approached the Sun several times. Its next passage would be its second entry into the inner Solar System. Suffice to say that this visit would be considered a historic event.
At present, scientists assume that the comet came from the Oort cloud, a place – still hypothetical – located around the Solar System which would be the origin of trillions of comets.
This diagram compares the size of the solid, icy core of comet C/2014 UN271 (Bernardinelli-Bernstein) to several other comets.
NASA
(vja)