We could be the last humans to see the green comet passing Earth for the first time since the Ice Age. Here's how, where, and when to watch it.

Astronomers recently discovered a green comet approaching Earth for the first time in 50,000 years.
Here's how, where, and when to see Comet ZTF as it passes Earth in late January and early February.
The comet will be closest to the Earth on February 2.

We could be the last humans to ever see the green comet hurtling past Earth from the outer reaches of the solar system in late January and early February.

C/2022 E3 (ZTF), or Comet ZTF for short — the name astronomers gave this space snowball after the Zwicky Transient Facility discovered it in March — hasn't been in our cosmic neighborhood since the last Ice Age.

Researchers calculated that the icy ball of gas, dust, and rock orbits the sun roughly ever 50,000 years, which means that Neanderthals were still walking the Earth and humans had just migrated out of Africa for the first time when the comet last whizzed by.

With no telescopes or binoculars, those ancient peoples may not have spotted the comet at all. And there may never be an opportunity to see it again.


"Some predictions suggest that the orbit of this comet is so eccentric it's no longer in an orbit — so it's not going to return at all and will just keep going," Jessica Lee, an astronomer at Royal Observatory Greenwich, told Newsweek.

So it might be worth the effort to look for Comet ZTF and become one of the few humans to ever see it up close. Here's what you need to know to maximize your chances.

When to see the green comet
Man stargazing with a telescope
You may need a small telescope to spot Comet ZTF, but binoculars could be enough. Bryan Allen/Getty Images
In the Northern Hemisphere, the green comet was visible just before dawn in late January, according to NASA. Amateur astronomers took photographs of the green comet to show what you could see.

A completely shaded new moon provided ideal dark skies for spying the comet on January 21.


If you missed that, your last, best chance to see the comet in the Northern Hemisphere was on and around Monday, January 30, when ZTF was between the end of the Big Dipper and Polaris, the North Star.

Then on early February 1 and February 2, the comet will be visible in the Southern Hemisphere, when it makes its closest pass by Earth since the stone age at around 26 million miles away, according to Earth Sky. That's nearly 109 times the average distance of the moon, but the comet is burning so bright that it could still be visible in the night sky.

The comet is expected to be brightest on January 31 and February 1, though the moon will be bright and the comet will be "the faintest an object can be seen without optical aid in a very clear, very dark sky," according to the Adler Planetarium.

It's important to set yourself up for success if you're trying to spot it

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