Approaching Earth in 2023, comet C/2022 E3 (ZTF) will be visible in the sky for a few weeks. But when will that be?
Berlin – A rare visitor approaches Earth in early 2023. Only every 50,000 years does comet C/2022 E3 come as close to Earth as it did in January 2023. However, it was not discovered until March 2, 2022 by the Zwicky Transient Facility, which is why it is only called ZTF for short. The Zwicky Transient Facility is a wide-field astronomical survey of the sky, with the camera sweeping the entire northern sky every two days.
There have already been thousands Supernovae and hundreds of asteroids and comets discovered. Comet ZTF was about 400 million miles from Earth when it was discovered. This corresponds to 4.4 astronomical units – the mean distance from the earth to the sun, which is abbreviated as AE and covers approximately 150 million kilometers.
Bright or dark: how visible is comet ZTF?
During this time, the comet was mag 17.3, which is not bright at all for magnitudes. The lower the number, the brighter the object. The value describes the apparent brightness of a star or other celestial body. For the sun, the value is −26.832 mag, our moon is −12.73 mag bright, and Mars still manages to −2.91 mag. At the time of discovery, the brightness of the ZTF comet was more in a league with the dwarf planet Eris, whose magnitude is 18.8. It orbits the sun beyond the orbits of Neptune and takes almost 560 years to orbit the sun.
On January 12, 2023, ZTF is expected to reach its closest point to the sun, perihelion. The earth only reached this on January 4, 2023 during its journey around the sun. The comet will then approach our parent star to within 1.1 AU. ZTF is scheduled to reach its shortest distance to Earth on February 1, 2023. Then there are 0.28 AU or almost 42 million kilometers between the comet and the earth. This means that comet C/2022 E3 is getting closer to Earth than Mars, which has the smallest Earth-Mars distance of 55 million kilometers, will ever come.
It is expected to reach magnitude 5.5 in late January and early February 2023, making it as bright as the planet Uranus. However, it will be very difficult to observe during this period. The last new moon will be in the sky on January 21, 2023. In the next few days, the Trabant will be up to his Full moon phase on February 5, 2023 reflect more and more sunlight to the earth. This will make the nights longer again and obscure objects like Comet ZTF will be difficult to see.
Comet C/2022 E3 (ZTF) Observation Tips: This is the best way to see it
With binoculars, there might still be some good viewing opportunities. In early January it is still in the morning sky, but will gradually become a nocturnal object over time. At its brightest it will show up near Polaris. Shortly after the Full Moon, on February 6, 2023, it will pass the star Capella in the constellation Auriga.
But even if Comet ZTF will move away from Earth again after February 1, 2023, another observation window will open in the evening sky, especially in the second week of February. Then C/2022 E3 will still be about 6 mag bright. Meanwhile, the fullness of the moon is decreasing again and the nights will be less bright.
Comet ZTF will pass Mars on the night of February 10-11, 2023. From February 15 to 16, 2023, ZTF will appear next to the star Aldebaran in the constellation Taurus. At this point in time, its brightness is still 7 mag – so it will hardly be recognizable even with binoculars.
Comet C/2022 E3 (ZTF): Late sighted, early recorded
Although C/2022 E3 (ZTF) was only discovered in March 2022, it was also shown to have been sighted on images from July 10, 2021 by the Pan-Starr (Panoramic Survey Telescope And Rapid Response System) on Hawaii. At that time its brightness was 23 mag. In October and November 2021, he narrowly escaped the eyes of the ZTF.
ZTF on the other planets: That’s how close it comes to them
From mid-February, the comet will only be visible to us with special astronomical telescopes. However, he will approach a few planets on his journey through the solar system. It will approach Mars on February 21, 2023 at 0.46 AU (about 68 million kilometers) and Venus on March 19, 2023 at 1.06 AU (about 159 million kilometers). With 4.9 AU (about 733 million kilometers) the comet ZTF flies past Jupiter on July 17, 2023. ZTF reaches its closest point to Saturn on October 19, 2024 with 9.6 AU and thus at a distance of 1.4 billion kilometers.
When ZTF reaches its farthest point, the aphelion, it is 2,800 AU from the Sun. That is around 420 billion kilometers. That’s why you should take advantage of the open-air opportunities in January and February 2023. Even if some media speak of observation with the naked eye: you are on the safe side with binoculars or a small telescope.
We have more astronomical events for this year in our astronomical year preview 2023 summarized – and the Highlights of space travel 2023 we have also written it down for you.