Approaching comet – Comet C/2022 E3 (ZTF) could even become visible to the naked eye at the end of January

Sky spectacle at the beginning of the year: A long-period comet is approaching Earth and could even become visible to the naked eye by the end of the month. Because the slightly greenish glowing comet C/2022 E3 (ZTF) will reach the point closest to the sun on January 12th and the closest point to the earth on February 1st – it will then pass us at a distance of only 42 million kilometers. In the next few weeks, the comet will therefore increase significantly in brightness and be easily observable.

If halleyLovejoy or C/2020 F3 Neowise: Comets visible to the naked eye offer a fascinating celestial spectacle and fascinated our ancestors. These icy chunks from the Kuiper belt or the Oort Cloud are heated as they approach the inner solar system and begin to tail and often greenish shimmering to form a coma.

Orbit of Comet C/2022 E3 (ZTF).© NASA/JPL-Caltech

50,000 years for one solar orbit

Now one of these icy messengers from the outer reaches of our solar system is on its way to us again: The long-period comet C/2022 E3 (ZTF) was discovered on March 2, 2022 by the telescope of the Zwicky Transient Facility in California. At that point, the comet had just passed Jupiter’s orbit and was still a good 400 million miles away. At first, astronomers thought it was an asteroid – until the object developed a tail a little later.

It is now clear that C/2022 E3 (ZTF) is a long-period comet that takes around 50,000 years to orbit the sun. Its trajectory is highly eccentric, almost perpendicular to the plane of the planets. The comet oscillates on this orbit from its furthest point from the sun at a distance of around 2,800 astronomical units to its closest point at around 1.1 astronomical units from the sun.

Soon bright enough for the naked eye or binoculars

In the meantime, comet C/2022 E3 (ZTF) has approached so close that it can be seen well even with smaller telescopes. It has already developed a greenish glowing head and a yellowish dust tail. A weak ion tail is also visible. The icy chunk moves in rapid succession through the constellations of Coronet, Boötes, Draco and Ursa Minor throughout January, steadily increasing in brightness. On January 12th it passes its closest point to the sun.

sky map
From January to March 2023 the path of comet C/2022 E3 (ZTF) visible in the sky.© Union of Sternfreunde eV/www.sternfreunde.de

On February 1, the comet will then also pass the closest point on its trajectory: It will then fly past us at a distance of only 42 million kilometers and reach a brightness of magnitude 5.5. That means it should even be visible to the naked eye from dark locations. The comet can best be observed shortly before the end of January, when it has already reached its greatest brightness and shines high in the sky near the North Star throughout the night.

In mid-February the comet was no longer visible to the naked eye, but two close encounters in the sky can then be observed with a small telescope: On 10./11. February he will pass close to Mars, on 15./16. February is right next to the star Aldebaran, the glowing reddish “eye” of the constellation Taurus.

Source: Max Planck Institute for Astronomy, Sky & Telescope

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