For the first time in 80,000 years, this celestial body is approaching our planet and should, in the days to come, offer a magnificent spectacle to the most observant.
It is called C/2023 A3, Tsuchinshan-Atlas, or simply the “comet of the century”, according to some specialists. This astral phenomenon of considerable magnitude, which has been traveling in the skies for millions of years, is coming closer and closer to Earth for the first time in 80,000 years, to the great joy of astronomy enthusiasts, indicates the Futura-Sciences website.
Visible in the northern hemisphere from October 13
The small body of rock and ice was detected in January 2023 by China’s Purple Mountain Observatory (Tsuchinshan), giving it the first half of its name. He owes the second to the confirmation of his existence by a telescope from the South African ATLAS program.
Until now, you had to be in the Southern Hemisphere to hope to see it with the naked eye. On the social network X, many Internet users located in this area have already immortalized his passage.
In the Northern Hemisphere, it will be visible from October 13 until the 30 of the same month. If the weather is suitable “it will be obvious” every evening when looking “in the direction of the setting sun”, according to Lucie Maquet, astronomer at the Institute of Celestial Mechanics and Ephemeris Calculation (IMCCE), located within from the Paris-PSL Observatory.
The study of her career is too short, “barely a year of hindsight”, to know precisely the path she has followed until now, she adds. It follows an orbit “which is not closed”, with models suggesting that it could have been up to 400,000 times the Earth-Sun distance before reaching us.
Risks of destruction
Late Friday afternoon, the comet traveling at a speed of 240,000 km/h from the Oort cloud “risked” its life by passing as close as possible to the Sun. When comets approach our star, the ice contained in their core sublimates and lets out a long trail of dust, reflecting sunlight.
This characteristic hair, the coma, is also a sign that the object is “degassing”. The whole question is whether this degassing will not be too great, at the risk of disintegrating the unwary visitor.
A catastrophe “always possible”, according to the astronomer, because the assembly of ice and stones “may very well not resist the force of gravity of the Sun”. The good news is that C/2023 A3 appears to have a very massive core, and therefore “there is a good chance that it will survive” this passage.
The first forecasts, revised downwards since, suggested that it would have exceptional brightness as it passed near the Earth. “It’s a bit of a surprise at the last moment, but in any case it’s going to be a brilliant comet, that’s for sure,” according to Lucie Maquet.
Unpredictable course
As for its future course, it is unpredictable. Her solar odyssey will not be without consequences on her orbit, disrupted by the gravity of the stars she will have encountered and by the weight loss cure inflicted by the Sun.
It follows an orbit that is not closed, with models suggesting that it may have been up to 400,000 times the Earth-Sun distance before reaching us.
The models used predict, without any commitment, that it could be “ejected from the solar system, to get lost between the stars”, according to the September IMCCE bulletin.
Everything will ultimately depend on the encounters that C/2023 A3 will make during its journey through the Oort cloud, a few thousand years from now. It would be enough, notes the astronomer, for it to “encounter a body which deflects it enough for it to return for a trip through the solar system”.
