Once-in-a-lifetime green comet approaching closest point to Earth

Comet C/2022 E3 (ZTF) has already been visible through binoculars and telescopes this month, but could become visible with the naked eye as it gets ever nearer to our planet.

Experts say those without equipment should try to catch it on 1 and 2 February, when the green comet will look its brightest against the night sky.

At its closest point (a mere 28 million miles away), it will be visible from the northern and southern hemisphere.

NASA described the comet's rare fly-by as an "awesome opportunity to make a personal connection with an icy visitor from the distant outer solar system".

When is the best time to see it?

Until now, the visibility has been at its best before dawn.

But as January winds down and February begins, the comet will be visible from the evening onwards.

The comet will be at its nearest and brightest between next Wednesday and Thursday.

However, the Royal Observatory at Greenwich suggests you check what time the moon will rise where you live, so to avoid its bright light drowning out the comet's shine.

And while C/2022 E3 (ZTF) has been tipped to be one of the very best comet sightings of 2023, it won't be quite as stunning as the Neowise comet from three years ago.

That one left a picturesque streak behind it as it flew by Earth.

Binoculars and telescopes have made the comet easy to spot since 12 January.

But even without such equipment, there are ways you can give yourself a better chance of seeing it as it gets closer.

Stargazing apps like Night Sky, SkyView and Sky Guide can be a great utility, as they can help you find the precise location of comets by helping you map constellations of stars.

By pointing your smartphone's camera up at the night sky, such apps will use augmented reality to tell you which constellations you're looking at and offer tips on how to spot comets.

When the green comet gets closest to Earth, it will be in the Camelopardalis constellation.

If you want to try and see it before then, it's travelling through Corona Borealis, Bootes, Draco, and Ursa Minor.

What else do we know about C/2022 E3 (ZTF)?

The icy green comet was only discovered on 2 March 2022, spotted from the Zwicky Transient Facility in California.

Astronomers calculated that it had an orbital period - the time it takes to travel round the sun - of 50,000 years.

That would put its last journey this close to Earth as back in the Stone Age.

The comet is thought to have originated in the outskirts of the solar system in the Oort Cloud.

NASA describes the cloud as a "collection of icy objects farther away than everything else in the solar system".

It's so far away that no spacecraft have yet been sent to explore it, though there are some en route.

Unfortunately, it will take so long for them to get there that they will be long out of power by the time they arrive.

-sky news