Towards the end of this month we will have a unique opportunity to see a comet that approaches the Sun and Earth every 50.000 years.

Comet C-2022 E3 was first spotted last March when it was passing by Jupiter. Approaching from the far reaches of the solar system, it will be closest to the Sun the day after tomorrow and, after orbiting it, will be closest to Earth on February 1, when it will be easiest to spot in the sky. Astronomers indicate that C-2022 E3 will certainly be visible with a small telescope or binoculars, and perhaps even without them, if the night is clear, without the Moon and without light pollution from urban centers.

- The comet with a diameter of about 1 kilometer is composed of ice and dust and due to its proximity to the Sun it has a greenish aura - explains Nicola Biver, an astrophysicist from the Paris Observatory. It is significantly smaller than NEOVISE, the last comet visible without a telescope, which passed Earth in March 2020, and especially the 60-kilometer-diameter Hale-Bopp Comet, which was clearly visible in the sky for days in 1997.

Although small, the newly discovered comet will be visible as it passes much closer to Earth. It will pass closest and be brightest in the first week of February, but during that period the Moon will be full. Beaver explains that in the Northern Hemisphere the comet will be easier to spot in the last week of January, when the moon is new. It will be visible in the sky between the constellations Ursa Minor and Ursa Major.

The comet comes from the Oort Cloud, a belt of mysterious icy objects at the very edge of the Solar System. The last time C-2022 E3 came close to Earth, Neanderthals could see it. Beaver points out that this could be the comet's last trip around the Earth, because due to the elongated elliptical orbit it could be completely thrown out of the Sun's gravitational influence.

The James Webb Space Telescope's instruments will be pointed at C-2022 E3 to determine the composition of the comet and its tail – the surface layer of ice melted by the sun's rays.

- The rare visitor will give us information about the elements of the solar system that are several times farther than the most distant planets - says Thomas Prince, professor of physics at the California Institute of Technology.