The ancient Greeks had an idea that comets were a sign that something good or bad was about to happen.

So what about this “green comet” that will soon be visible, to some extent, in Australian skies?

In these uncertain times, does it bring glad or ill tidings?

Bit of a mystery

This once-in-many-lifetime comet – sexily named Comet C/2022 E3 (ZTF) – was discovered, in the region of Jupiter, only in March last year.

It’s thought to have originated in the theoretical Oort Cloud – a prediction, really, that a ring of ice particles surrounds our solar system for trillions of kilometres.

What appears to be an emerald lit from within – when seen through a high-end telescope – the comet is thought to have last visited the inner solar system 50,000 years ago.

It made its closest approach to the sun on January 12. It then did a sharp turn around the sun and will come within 42 million kilometres of the Earth on February 2.

Worth seeking out

While the big media outlets have been advising readers to keep their eye out for the great green glow in the sky – starting this week – astronomers have been urging people to keep their expectations in check.

Also, it’s good to know that the green glow – caused by an interaction between the sun’s subatomic particles and a form of carbon that exists in the dust surrounding the coma, or body, of the comet.

The comet made its sharp turn around the sun in mid-January. Image: JPL

A spoilsport at Forbes said it was possible to see comet C/2022 E3 from your backyard. “But only if you have a lot of patience, a decent pair of binoculars or a small telescope… and expectations that are really rather low indeed. You also need to wait a few weeks to see it at its brightest.”

And it won’t look green – “definitely not through a pair of binoculars”.

The reliable word is that you’re likely to see it as a smudge above the horizon in the morning skies.

And if you’re a romantic, know that it will hang around until Valentine’s Day.

At least you can revel in the mystery

A consistent message from experts and the optimistic news reports is that comets are unpredictable.

Where and when they will turn up, who can say for sure?

As for Comet C/2022 E3 (ZTF), modelling by some astronomers say that this enigmatic traveller with an emerald glow will never return to our neighbourhood.

Which brings us back to the big question: Is it making some kind of prophesy on its farewell tour?

Comets and destiny

Back in 1066, the appearance of Halley’s Comet proved to be favourable for William the Conqueror at the Battle of Hastings.

While his opponent, King Harold, made a few mistakes, he suffered some genuine bad luck.

Could the new comet favour victorious luck for the Ukrainians over the Russians?

The 11th century Bayeux Tapestry showing the Battle of Hastings with a comet in the sky.

Sure. It’s a silly idea. But some people will be desperate enough to hope for cosmic intervention in the war – or in personal matters.

Jesus was born under a comet, it’s said.

So what might the green comet bring to bear?

It has form for bigger events

Comet C/2022 E3 (ZTF) was only discovered last March by the Zwicky Transient Facility in California – but modelling says it last visited our inner solar system 50,000 years ago.

There was a lot going on back then. Nothing less than the future of the human species what it would look like.

Did the artists at Burrup Peninsula see the green ghost in the sky? Photo: Ken Mulvaney

Our species, Homo sapiens, were finding our feet – and some of us were fooling around with our cousins the Neanderthals. Talk about star-crossed lovers!

It’s thought that 50,000 years ago, the last remnants of Homo erectus were dying out in Asia after nearly two million years. Perhaps they saw the green comet and intuited dark meaning from it.

Back then, in Australia, there were wombats and tortoises the size of cars, 450 kilogram kangaroos. These, too, began their slide to extinction around the time of around the time of the green comet’s visit.

On a cheerier note, 50,000 years ago was also, according to some experts, when the Burrup Peninsula rock art in Western Australia was produced.

It’s spooky to imagine those artists looking up from their work on an early morning and wonder what the hell?

You can do the same for the next couple of weeks.