A newly discovered comet could be visible to the naked eye as it passes Earth and the Sun in the coming weeks for the first time in 50,000 years, astronomers have said.
The comet is called C/2022 E3 (ZTF) after the Zwicky Transient Facility, which first spotted it passing Jupiter in March last year.
After traveling from the icy expanses of our solar system, it will come closest to the Sun on January 12 and pass closest to Earth on February 1.
It will be easy to spot with a good pair of binoculars and probably even with the naked eye, as long as the sky is not overly lit by city lights or the Moon.
The comet “will be brightest when it’s closest to Earth,” Thomas Prince, a physics professor at the California Institute of Technology who works at the Zwicky Transient Facility, told AFP.
Composed of ice and dust and emitting a greenish aura, the comet would be about one kilometer (0.62 miles) in diameter, said Nicolas Biver, an astrophysicist at the Paris Observatory.
This makes it significantly smaller than NEOWISE, the last comet visible to the naked eye, which passed Earth in March 2020, and Hale-Bopp, which swept through in 1997 with a life-threatening diameter of around 60 kilometers.
But the new visit will come closer to Earth, which “could make up for the fact that it’s not very big,” Biver said.
While the comet will be at its brightest as it passes Earth in early February, a fuller moon could make it difficult to detect.
For the northern hemisphere, Biver suggested the last week of January, when the comet passes between the constellations Ursa Minor and Ursa Major.
The January 21-22 weekend new moon offers good luck for astronomers, he said.
“We might also have a nice surprise, and the object might be twice as bright as expected,” Biver added.
Prince said another opportunity to locate the comet in the sky will present itself on February 10, when it passes near Mars.
The comet has spent most of its life “at least 2,500 times farther than Earth is from the Sun,” Prince said.
Biver said the comet would originate from the Oort Cloud, a theorized vast sphere surrounding the solar system that is home to mysterious icy objects.
The last time the comet passed through Earth was during the Upper Paleolithic period, when Neanderthals still roamed the Earth.
Prince said the comet’s next visit to the inner solar system was expected in 50,000 years.
But Biver said there was a possibility that after this visit the comet would be “permanently ejected from the solar system”.
Among those watching closely will be the James Webb Space Telescope. However, it won’t take images, but rather study the composition of the comet, Biver said.
The closer the comet is to Earth, the easier it is for telescopes to measure its composition “as the Sun boils off its outer layers,” Prince said.
This “rare visitor” will give us “information about the inhabitants of our solar system far beyond the most distant planets”, he added.
© Agence France-Presse