J.R. Johnson

My mother, ever curious, wanted to know what all the “green comet” fuss is about. Here’s a quick guide to C/2022 E3 (ZTF), a visitor last welcomed to these parts by Neanderthals.

A lot has changed since then!

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See a rare green comet closest to the sun on Jan. 12 in livestream | Space

NASA’s Jet Propulsion Labs (NASA JPL) gives the period of this comet as 50,000 years. This means the last time the orbit of C/2022 E3 (ZTF) brought it so close to the Earth, our planet was in the midst of the last glacial period or “ice age” and early Homo sapiens and Neanderthals still shared the planet.

Pretty pictures: A dazzling green comet has stargazers thrilled in amazing photos | Space.

How to Watch the Green Comet During the New Moon – The New York Times

Comets are clumps of dust and frozen gases, sometimes described by astronomers as “dirty snowballs.”… 

“They’re alive,” Laurence O’Rourke, an astronomer with the European Space Agency, said. “When they’re far from the sun, they’re sleeping, and when they get close to the sun, they wake up.”

[Nothing to worry about then. It’s fine!]

…

To catch the comet, look north.

On Jan. 21, the night of the new moon and thus the darkest skies, the comet will be close to Draco — the dragon-shaped constellation that runs between the Big Dipper and the Little Dipper.

Over the following nights, the comet will creep along the dragon’s tail. And on Jan. 30, the comet will reside directly between the Big Dipper’s “cup” and Polaris, the North Star. If you’re accustomed to finding the North Star by following the two stars on the end of the Big Dipper’s cup, then you should be able to spot the comet. Simply scan that imaginary line until you see a faint smudge.

…

For anyone living above the 35th parallel — imagine a curving East-West line running from North Carolina through the Texas Panhandle out to Southern California — the comet will be visible all night starting Jan. 22.

So C/2022 E3 (ZTF) is going to be visible for a while, but you might need binoculars. What did the Neanderthals think of it and its dramatic green halo, I wonder? 

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