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AstronomyAfter 50,000 years, a comet returns to shine in our sky
The weekend of January 21 and 22 and the week that follows, you will have to keep your eyes turned to the sky. A comet from the confines of the solar system will be visible for the first time in 50,000 years.
Comet “C/2022 E3 (ZTF)” will reach its perihelion, that is to say its closest point to the Sun, on January 12.
AFP
Its last visit dates back 50,000 years: comet “C/2022 E3 (ZTF)”, coming from the confines of the solar system, will pass close to the Sun this week and might be visible to the naked eye at the end of January. The small, rocky, icy body, estimated to be regarding 1 km in diameter, was discovered in March 2022 by the Zwicky Transient Facility (ZTF) astronomical sky survey program which operates the Samuel-Oschin Telescope at the Palomar Observatory, in California.
The comet will reach its perihelion, ie its closest point to the Sun, on January 12, according to astronomers’ calculations. The celestial object will then be “10% further” from the Sun than the Earth is (regarding 150 million km), specifies Nicolas Biver, of the Paris-PSL Observatory.
January 21 and 22, best viewing window
When a comet approaches the Sun, the ice contained in its nucleus sublimates and lets out a long trail of dust reflecting the light of the Sun. It is this shiny hair that we will be able to observe from Earth, as “C/2022 E3 (ZTF)” comes towards us.
The best viewing window should be the weekend of January 21-22 and the week following. The star will be easily spotted with a good pair of binoculars, and perhaps even with the naked eye during part of the night, under a sky without too much Moon and free from light pollution.
His last visit
According to current models, comets come from two reservoirs: the Kuiper belt, beyond the orbit of Neptune, or the Oort cloud, a vast theoretical zone located up to a light year from the Sun, at the limit of its gravity field. “According to the inclination of the plane of its orbit, it would be a long-period comet originating initially from the Oort cloud”, according to Nicolas Biver.
After being propelled towards our lands, approximately 50,000 years ago, the comet then left in the other direction, but without going as far as the Oort cloud. This time around, she’ll likely end up “permanently ejected from the solar system.”
His final visit will be an opportunity for scientists to understand a little more regarding the composition of comets, in particular thanks to observations by the James Webb Space Telescope. This “rare visitor” will bring “information regarding the “inhabitants” of our solar system far beyond the most distant planets”, adds Thomas Prince.
(AFP)