Deep in the Stone Age, when Neanderthals lived next to us homo sapiens, our ancestors may have been excited to see a green light in the night sky. Well, this light –C/2022 E3 (ZTF) (known as the Green Comet)– is back.
The Green Comet’s highly elliptical orbit means it will be a long time before it swings past Earth again – about 50,000 years to be precise. And it will if it repeats its 50,000-year sojourn, which it may not.
Astronomers discovered the comet in March 2022 using the Samuel Oschin robotic telescope at the Zwicky Transient Facility. It passed perihelion (when it is closest to the sun) on January 12.
Observers in the US can see the comet now through early Februarypossibly with the naked eye if you are in one dark field of vision, but your chances are better if you use binoculars or a telescope. According to NASA, the best time to see the comet is in the morning hours.
The comet will make its closest approach to our planet on February 2nd. The closest approach will be about 0.29 AU (about 27 million miles) from Earth, according to EarthSky.
Currently, the comet is toward the constellation Boötes and near Hercules, EarthSky reports. (If you have trouble finding the position of the comet, you can consult a handy interactive sky map.) Those of the comet Location makes it difficult for observers in the southern hemisphere to see anything. From its current position in the night sky, its projected path shows it past Ursa Minor (the Little Dipper), passing by Camelopardis at its closest approach.
Comets shine thanks to a combination of their chemical composition and sunlight. Comets that pass near the Sun are illuminated and heated by its energy, causing molecules on their surface to vaporize and fluoresce. Comet heads glow green if they contain cyanogen or diatomic carbon, according to NASA.
The Green Comet can reach magnitude 5 by the time it is closest to Earth. according to EarthSky. The lower the number, the brighter the object. The full moon apparent magnitude is about -11, and the faintest objects seen by the Hubble Space Telescope are about magnitude 30. to Brittanica. The darkest stars our naked eye can see are about magnitude 6.
While the comet can reach magnitude 5, it will It can be helpful to use binoculars or a telescope if you have trouble seeing the object on a clear night.
The incoming space rock isn’t the only recent green comet; 2018 Comet 46P/Wirtanen was bright enough to be seen by naked eye observers, and in 2021Comet Leonard glowed green as the ball of ice made its cosmic trajectory.
So keep an eye out for the upcoming clear nights. If you see something with a faint green glow, it’s probably our newest cosmic visitor.