By Chris Skeldon 
Comet C/2022 E3 (ZTF) made its closest approach to Earth this morning before it likely leaves our solar system for good. But it can still be observed in the next few days from the northern hemisphere.
Discovered by astronomers Zwicky Transit Attachment (ZTF) At California’s Palomar Observatory, Comet C/2022 E3 (ZTF) orbits the Sun once every 50,000 years, which means it last passed our planet in the Stone Age, yet the mysterious Stonehenge formation was not built.
What are comets and why is this one green?
Comets are primordial balls of dust and ice that revolve around the sun in giant elliptical orbits. As they approach the Sun, these celestial bodies heat up, turning surface ice into gas and expelling dust. In this way a cloud (or eat or hair – Haze surrounding comet nuclei) that surrounds the comet’s solid nucleus and associated dust tail.
C/2022 E3’s (ZTF) green glow is due to the presence of diatomic carbons — pairs of carbon atoms bonded together — in the head of the comet. The molecule emits green light when the sun’s ultraviolet rays hit it.
How to observe a comet in the northern hemisphere
To see the comet, choose a dark place devoid of artificial lights and wait about 30 minutes for your eyes to adjust. Look to the north just after sunset and find a slight greenish glow. The comet may be visible to the naked eye, but binoculars will certainly make the job easier.
Amateur astronomers observe comet C/2022 E3 (ZTF) in Omsk, Russia, February 1, 2023.
Alexey Malgavko/Reuters
On its way, the comet will pass the Polar Star, the brightest star in Ursa Minor. This is the best time to see it, in the first two days of February. Starting in the middle of the month, the comet “darkens” as it continues its journey into the outer reaches of the solar system, on its return trip to Earth. Oort cloud.