C/2022 E3 (ZTF)

Designation: C/2022 E3 (ZTF)
Hemisphere: Northern
Constellation: Auriga (in this photo)
Object type: Long-period comet


C/2022 E3 (ZTF) is a long-period comet that originated from the Oort cloud. It was first discovered in early March 2022 by astronomers using the wide-field survey camera at the Zwicky Transient Facility (hence the “ZTF” in its designation).

According to astronomers’ estimations, the comet has an orbital period of approximately 50,000 years ago, meaning that Neanderthals were still walking the Earth last time the comet came close to us.

The comet has been nicknamed “The Green Comet” due to the bright green glow around its nucleus, which is caused by the effect of sunlight on diatomic carbon and cyanogen. The green hue is typical of comets with a high gas content.

The comet nucleus was estimated to be about a kilometre in size, rotating every 8.7 hours, while its tail of dust and gas extended for millions of kilometres. The comet’s brighter greenish coma, short broad dust tail, and long faint ion tail stretch across a 2.5 degree wide field-of-view.


Mount: ZWO AM5
Main Telescope: William Optics Redcat 51
Main camera: ZWO ASI294MC-Pro
Main camera filter: Optolong L-Pro
Guidescope: William Optics 32
Guide camera: ZWO ASI220MM Mini

Acquisition details

Total integration time: 3 hours
Acquisition: ZWO AsiAir Plus
Processing: PixInsight
Location: Luxembourg

Where the universe begins…