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

C/2022 E3 (ZTF) comet is visible with the naked eye from certain locations

What is a ‘green comet' and where can you see it?

A green comet is flying past Earth for the first time in 50,000 years, offering skygazers a one-off opportunity to witness the celestial spectacle before it disappears from our Solar System forever.

The C/2022 E3 (ZTF) comet made its closest approach to Earth on 1 February, 2023, but will continue to be visible throughout the week from anywhere in the northern hemisphere – weather permitting.

At a relatively close 42 million kilometres (26 million miles) from our planet, and with a brightness value of the magnitude of about +6, it will be possible to see it with the naked eye.

The comet is so rare that woolly mammoths and saber-toothed cats were still roaming the Earth when it last swept by our planet.

To find out where in the sky to look, and learn when conditions are best for viewing the comet tonight and over the next few days, you can follow our live coverage in the blog below.

Key Points

• Nasa ‘expecting new discoveries’ from green comet
• Where the best viewing conditions for the green comet are right now
• How to see the green comet
• Much more to see in February’s night sky

[1 February 2023 03:53 · Vishwam Sankaran]

What we know about green comet's chemical composition

The comet’s green colour is due to the effect of sunlight on its molecules cyanogen and diatomic carbon.

The latter is a green, gaseous chemical with the chemical formula C=C that occurs in the carbon vapour in comets.

These molecules are broken down by sunlight into single carbon atoms before they move into the comet’s tail.

Thus the green colour is limited to the space rock’s icy nucleus while the tail may still appear white in contrast.