Why is the C/2022 E3 (ZTF) comet green? What does the comet’s name code represent?
The space-faring rock will speed past the Earth for the first time in 50,000 years and will be visible tonight, February 1st.


The C/2022 E3 (ZTF) comet, catchy name I know, will soon be visible in the night sky. It is expected to be visible on 1 February, 2023, passing within 28 million miles. It doesn’t sound close but it’s actually the closest it has travelled to our planet for 50,000 years. For a bit of context humans were still hunter-gatherers then as well as living with neanderthals.
Comet spotters will be looking out for a key marker of the rock; its green colour. This is likely due to the presence of diatomic carbon. Due to a number of complex scientific actions the head of the comet appears green due to the presence of this, but the tail doesn’t.
Comet C/2022 E3 (ZTF) this morning from Orlando, FL. Tracked for 90 minutes (180s subs) with my Redcat 71 and ASI6200MC. Stacked and edited on Adobe Premiere Pro. #CometZTF #comet ☄️ pic.twitter.com/ufQfLDMj6H
— Antonio Paris (@AntonioParis) January 27, 2023
You can watch the live webcast of the comet beginning at 11:00 p.m. EST on As USA.
What does the comet’s name code represent?
- The “C” indicates a non-periodic comet. This means it takes more than 200 years to orbit the sun.
- “2022″ marks the year discovered.
- “E3″ shows it was the third comet discovered in the fifth half-month (F is the other half-month of march).
- ZTF stands for Zwicky Transient Facility as this was the observatory the comet was first discovered at.