A comet unseen since early Homo sapiens roamed the Earth.
Comet C/2022 E3 (ZTF), also called ‘Green Comet’, will make its closest pass to our planet on February 1.
And like other comets with long orbital periods, it doesn’t orbit very often.
In fact, the ‘Green Comet’ last visited the inner Solar System 50,000 years ago, when Stone Age humans are thought to have first started developing language.
And due to the nature of its orbit, it may never visit the inner Solar System again – meaning this may be humanity’s last chance to see Comet C/2022 E3 (ZTF).
Luckily, there is still ample opportunity for skywatchers to get a glimpse of what has been hailed as the best comet of 2023.
What do we know about Comet C/2022 E3 (ZTF)?
The comet was discovered in March 2022 by astronomers conducting a wide-field celestial astronomical survey at the Zwicky Transient Facility in California, United States.
It has brightened significantly since then and is visible in the early morning sky from the northern hemisphere.
Known as perihelion, it made its closest approach to the Sun on January 12, while perihelion (Earth’s closest transit) will occur on February 1.
The star’s radiation became brighter as it passed the Sun, warming it and creating a green coma—a hazy envelope of gas made up of heated materials such as water, carbon dioxide, and carbon monoxide.
It also has a short, broad dust tail and a longer, faint ion tail formed when the solar wind interacts with the comet’s hair.
The green glow is a result of UV radiation from the sun illuminating the gases flowing from the comet’s surface.
C/2022 E3 (ZTF) is thought to come from the Oort Cloud, a region around the outer solar system thought to contain billions of comets, mostly in stable orbits around the Sun.
How to detect ‘Green Comet’?
It can currently be viewed with a telescope or binoculars in the early morning (predawn) sky from the Northern Hemisphere.
However, it is faintly visible to the naked eye when it reaches perigee in early February. At this point it will be about 42 million km from Earth and will also be visible from the Southern Hemisphere.
NASA warns that comets – and their visibility – are notoriously unpredictable.
C/2022 E3 (ZTF) is not predicted to form a tail that can be seen without a telescope, according to the Royal Observatory in Greenwich, London, but that could change.
For now, the comet looks like a fuzzy green ball in the sky.
The observatory advises that the comet can be “easily seen” with a telescope or binoculars from now until after perihelion, with best visibility in the pre-dawn hours.
From the end of January to the beginning of February, it will also be visible from the evening.
You can find out where the comet will appear in the sky by using a star tracking app.
To avoid disappointment when trying to see in the night sky, make sure there isn’t too much cloud cover, make sure you see the right side of the sky from your vantage point, and warm up and dress well before setting off. said the observatory.
He added that in order for your eyes to be sensitive enough in the dark, you should let your eyes adjust to the darkness for at least 15 minutes and avoid looking at cell phones or other bright devices.