Rare Green Comet the Focus of Pre-Dawn Stargazers This Week

by Mindy Cohn

A rare green comet, identified as C/2022 E3 (ZTF) but commonly called the "Green Comet," is a site to be seen in the northern night sky, according to NASA. 

The comet isn't as bright as Halley's or Hale-Bopp, but it should be visible to the unaided eye right before dawn in a dark sky if no clouds are blocking the view and if you are away from the city's lights. Using binoculars and small telescopes focused near Mars will also help from now through February 10. 

The Green Comet is a once-in-a-lifetime event as it takes more than 200 years to orbit the sun. It is also unique because of its color, which comes from its dicarbon molecules, chemical compounds with two bonded carbon atoms, and cyanogen. Both of these compounds look green when exposed to sunlight.

Comet C/2022 E3 (ZTF) was discovered in March 2022 by astronomers using the wide-field survey camera at the Zwicky Transient Facility at Mount Palomar, California. The comet's estimated size is 3,281 feet or more than half a mile in diameter.

It will come closest to Earth between February 1 and 2, passing by from  26 million miles away. 

Photo Credit: Flickr