While looking up at the sky towards the North Star on February 1 and February 2, look out for a green object to fly by.
No, it’s not a bird, it’s not a plane, and it’s not superman. It’s a green comet discovered by astronomers on March 2, 2022, at the Palomar Observatory in San Diego County, California. Using the Zwicky Transient Facility’s new camera attached to the Samuel Oschin Telescope, NASA says they were recently able to spot the comet passing by the sun on January 6.
This will be the first time the green comet can be observed since 50,000 years ago during the Old Stone Age (Upper Paleolithic).
Named C/2022 E3 (ZTF), the icy celestial object will be around 26- to 27 million miles away from the Earth. To put that in perspective, our moon is 235,000 miles away from Earth on average. So that’s approximately 100 times farther from Earth than the moon—to put your mind at ease.
The reason ZTF has a green flare has to do with the comet carrying diatomic carbon reacting with the sun’s outgassing particles. If the comet didn’t approach the sun as closely, the colors would be far less vivid, which makes this sighting so rare.
According to Bryce Bolin, one of the researchers credited with discovering the comet, ZTF is unique because it has two tails rather than one. Called an ion tail, it’s made up of ionized carbon monoxide, as well as carbon dioxide and nitrogen.
Considered a long-period comet, ZTF’s 50,000-year orbit isn’t considered that long when it comes to completing a single transit around the solar system. Other comets that come from the Oort cloud can take up to 1 million years to circle the solar system. While comets from this cloud are common, it’s not every day that a comet like this passes close to Earth, making the appearance of ZTF an occasion in the space community.
Bolin and co-discoverer Frank Masci were required to submit their findings to the International Astronomical Union in Paris. Once other astronomers confirmed the comet, it could be listed as C/2022 E3. Due to the collaborative nature of such discoveries, comets are no longer named after the people that first spot them.
Bolin estimates there are around 100 people involved in discovering a comet, including the makers of the telescope, designers, and so many others that come together to make the discovery happen.
For those interested in spotting the green comet on February 1 and February 2, it will be visible right off the handle of the Little Dipper in the Camelopardalis constellation. ZTF will only be visible in the night sky and is best viewed after midnight when it reaches its highest point. After that, the comet will continue its journey around the solar system, not returning for another 50,000 years.