Jake Massey
A rare green comet is making its closest pass by Earth.
The adorably named C/2022 E3 (ZTF) was last seen around 50,000 years ago and hails from the Oort cloud at the outermost edge of the Solar System.
The icy ball only orbits the sun once every 50,000 years, which means the last time it went past the planet was during the Stone Age – when Neanderthals roamed the Earth.
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Honestly, where the hell you been C/2022 E3 (ZTF)? So much has changed.
At its closest point, the green comet will be within approximately 45 million kilometres of us.
Dr Greg Brown, an astronomer at the Royal Observatory Greenwich, told the PA news agency: "Long-period comet C/2022 E3 is currently speeding through the solar system and won’t return for at least 50,000 years, assuming it ever does, so it's your once-in-a-lifetime chance to see it.
"Its path across our sky is taking it through the constellation of Draco the dragon and will be passing between the two bears, Ursa Major and Ursa Minor, in late January and into early February."
C/2022 E3 was first spotted in March 2022, using the Zwicky Transient Facility in California.
Its green glow is a result of ultraviolet radiation from the sun lighting up the gases surrounding the comet's surface, and it has recently become bright enough to see with the naked eye in areas with minimal light pollution.
Dr Brown said: "While it may yet become possible to see it with the unaided eye from an extremely dark site, you are much better off pointing a pair of binoculars or a small telescope at it.
"For observers in the UK, head out after midnight when the comet will be highest in the sky and try and find the faint greenish light coming from it.
"Easiest to see will be the brighter head of the comet, but, if you are lucky, you may spot one of its two tails sweeping out from it, each made of material being jettisoned from its rapidly warming icy surface."
If you're only considering staying up to see some alien-like green glow soaring through space, you should probably give it a miss though.
"You might have seen these reports saying we're going to get this bright green object lighting up the sky," Dr Robert Massey, deputy executive director of the Royal Astronomical Society, told the BBC.
"Sadly, that's not going to be anything like the case."
But if you are away from light pollution, have clear skies, binoculars and some luck, you might be able to make out a smudge in the sky. A once-in-a-lifetime smudge.