A one-kilometre-wide comet, known as the green comet, will be closest to Earth – 41.8 million kilometres away – on 2 February.
The Planetary Society says the comet has a solar orbit of roughly 50,000 years, which means it hasn’t been seen in the night sky since Neanderthal times.
You’ll have your best chance to see it is at night between 1 and 2 February.
NASA says the comet might be slightly visible to the naked eye but that amateur star searchers should not expect a bright-green light show.
“It won’t be green to the naked eye, maybe with a substantial telescope, but it will mostly be through astrophotography,” UQ astrophysicist Dr Ben Pope told ABC News.
“Nearly everything in astronomy is basically white to the naked eye except, like, red giant stars and Mars appears a little red, Jupiter is quite noticeably yellow.”
Due to light pollution, even seeing the comet with the naked eye could be a problem, unless you’re in a very dark part of the country.
“Basically, they’re very faint, you get a lot of people who go outside and wait and wait, and say, ‘I didn’t see anything’, but that’s because you’re in the inner suburbs. Even in outer suburbs it’ll be hard,” Dr Pope said.
According to a report in the Proceedings of the National Academy of Sciences, the green glow from some comets comes from the breakdown of a reactive molecule called dicarbon.
Do you try to look out for eclipses and comets?
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