Many are now calling it the “green comet” — rather than C/2022 E3 (ZTF), which is its real name — because of the greenish tint imparted to it in the photos by the clouds of carbon gas produced by the sun due to the heat it’s escaping its core.
And it’s called C/2022 E3 (ZTF) because it’s the third comet discovered during the “E” period (first half of March) of 2022 by an instrument called ZTF (Zwicky Transient Facility) installed in California is Mount Palomar Observatory. It’s a camera with a field of view large enough to survey the entire northern hemisphere sky every other day.
How to view C/2022 E3 (ZTF).
In March 2022, this comet was already closer to the Sun than Jupiter (600 million km) and 25,000 times less visible than the star least visible to the naked eye, the ZTF team had estimated at l era. On January 12, he came closest to the sun. She is therefore moving away from it and in this context she will be closest to us on February 1st.
Though it’s said to be “barely” visible to the naked eye, it’s still a bit visible provided you move away from the city lights. You need to face north, roughly in the direction of North Star: in the last days of January, it’s about halfway between the “Cup” of the Big Dipper and North Star. Astronomy software can help find it, depending on where you are, by searching for it by its real name.
In the early evening it will be lower on the horizon so the chances of seeing it can be higher a few hours later. Anyway, for anyone living north of the 35th parallel, it’s been in the sky pretty much all night since January 22nd.
However, all the astronomers consulted on the subject in recent days advise amateurs to arm themselves with binoculars, however humble… and be patient: the moon is in its waxing phase, the light it reflects the Sun can interfere with observations.
Where does this comet come from?
Its very elongated trajectory suggests it originated in the Oort Cloud, that vast expanse beyond the confines of our solar system. Given the distance this represents, astronomers estimate its last visit to our local area could date back as far as 50,000 years. However, this is a very rough estimate; and as for its future trajectory, given how close that orbit has brought it to the Sun – and the gravitational boost it will give – there’s a chance its next visit won’t be for another million years. Or even that the comet escapes the gravitational pull of our sun and continues on its way towards the stars.
The greenish color is not a unique phenomenon of this visitor: on the one hand, a comet is above all a large snow globe, each time one of them approaches the Sun, the heat partially melts it, causing clouds of gas. On the other hand, comets are made up partly of diatomic carbon (C2, or two bonded carbons), and this gives that green color when the gas escapes.