Green comet 2023 – live: How to see E3 in sky tonight before it disappears forever

Based on the green colour of the comet ZTF, astronomers say it contains molecules like diatomic carbon and cyanogen.

Diatomic carbon (C2) is a green, gaseous chemical with the formula C=C and is known to occur in the carbon vapour in comets.

While many comets glow green as they zoom past the Earth’s sky, it had for long remained a mystery why this hue never reached their tails.

Scientists as early as the 1930s had theorised that diatomic carbon that was created by the interaction of sunlight’s UV radiation and organic matter on the comet’s head was being further destroyed leading to the colour.

But the theory hadn’t been tested until late 2021 as diatomic carbon is not stable.

Timothy Schmidt, a chemistry professor at the University of New South Wales, demonstrated in 2021 the mechanism by which the dicarbon molecule is broken up by sunlight.

“The green colour comes from C2, which is itself a breakdown product of larger molecules in the snowball. The C2 breaks down into C atoms in a few days. The green is due to C2 absorbing and emitting light in a process known as fluorescence,” Dr Schmidt explained in a tweet on Tuesday.

Studying the chemical composition of comets like ZTF have unravelled several secrets about the formation of the Solar System.

ZTF belongs to a category called long-period comets that are known to emerge from a shell of space debris in the outermost stretches of the Solar System called the Oort cloud.

The Oort cloud hasn’t actually been viewed by astronomers, but is theorised to be a vast, spherical shell made of icy debris, some of which may be as old as the Solar System itself.

A recent study, surveying gases like carbon monoxide and water vapour in 25 comets, suggested that analysis of these molecules from comets could trace the chemical composition of the early Solar System.

Scientists could unravel insights about early solar systems based on the ratio of certain molecules present after outgassing from comets.

The research found, for instance, that comets very far from the sun that have never, or only rarely, orbited near the sun, produced more CO2 than CO, whereas those that have made many several trips close to the sun do the opposite.

Seeing the green comet can be tricky, even when you know where to look and the weather is good.

Capturing it for a timelapse video, however, is almost impossible. It requires no light pollution, clear skies and a specialist setup like this one. But the results are spectacular:

Although the green comet is making its closest approach to the Earth today, it may not be easy to view for many due to a bright moon and cloudy skies.

However, on 10 February, the comet would sweep next to Mars and this will also be after February’s full moon.

“The moon is bright tonight, making it difficult to find the comet with the naked eye. On Feb 10th, the comet will be slightly above Mars, as seen in this star chart from EarthSky,” The Canada–France–Hawaii Telescope (CFHT) joint facility tweeted.

Usually, comets have two tails – one that is made of ionised gas and another of dust.

The ion tail can be spotted as the small molecules on its side glow via fluorescence.

In the dust tail, large grains scatter the Sun’s UV light in all directions.

These two tails point in slightly different directions as the forces act on dust and ions in different ways.

But astronomers across the world reported a “third tail” on the green comet ZTF, which has been found to be just an “optical illusion.”

“Recently, a strange phenomenon has occurred with comet ZTF as it appears to have a third tail. This is, in fact, an optical illusion, due to our point of view of the dust trail,” European Space Agency’s Jorge Amaya explained.

There are few more days left when one can view the green comet zoom past Earth, says Milwaukee meteorologist Mark Baden.

The comet ZTF will still be visible in the days leading to 10 February, appearing in the night sky as a faint green smudge.

If the weather is favourable and clear with fewer clouds, one may see the comet in the night sky right of the north star.

People may still need binoculars or a telescope to view the comet.

The last time the green comet ZTF hurtled past Earth, Neanderthals may have seen its green tail “if they looked up from their cookfires,” says paleoecologist Jacquelyn Gill from the University of Maine in the US.

Dr Gill, who specialises in research on how the planet has changed since the last ice age, says modern humans – Homo sapiens – were just entering Europe when ZTF zoomed past Earth previously about 50,000 years ago.

“Some of the oldest cave paintings in the world, in Spain and Indonesia, date to this time,” she tweeted.

The human family tree during this time still had several more branches.

In addition to Homo sapiens, Dr Gill says, we had “Neanderthals, Denisovans, Floresians, maybe even others” when ZTF last flew past Earth.

The European Space Agency tweeted that it has been studying the green comet ZTF using its X-ray satellite XMM Newton in orbit since 1999.

Researchers had expected ZTF to be one of the brightest comets observed because of its bright green hue.

However, “disappointingly” the comet “barely showed up in the X-ray,” ESA said.

But the space agency noted that the observations and results are still “scientifically very valuable.”

With the UK and Ireland completely covered in cloud tonight, at least people in the US will have a better chance of seeing the green comet.

Severe winter storms will make it impossible for people in the South to see for the next few days, but a bit further west will see ideal conditions. Forecasts from The Weather Channel show that the best views will be from the South West and Pacific Coast regions of the United States.

Tonight will see clear skies all the way from Los Angeles in California to Denver in Colorado.

Here’s the full forecast for tonight:

Mike Narlock, the head astronomer at Cranbrook Institute of Science in Bloomfield Hills, Michigan, told The Dearborn Press & Guide about the best way to spot the green comet.

– Go outside after dark.

– Look for the Little Dipper constellation. This will help you locate the North Star, also known as Polaris, at the end of the handle.

– Above the North Star, you will find the constellation Camelopardalis, commonly called the giraffe. The green comet is visible inside that constellation.

– If you must look for the comet without any devices, try using peripheral vision.