Western University to host viewing party for once in a lifetime phenomenon

Comet C/2022 E3 will reach its closest point to Earth on Feb. 1, 2022. (Dan Bartlett/NASA)

It may be green in appearance but it isn’t envy that gives this comet its unique colour.

“Comets are usually white or blue. This one has a different colour,” says Paul Wiegert, professor of astronomy at Western University. “It's caused by a molecule which doesn't exist here really on earth. It's called dicarbon, but it can exist out in space. And some comets produce a lot of dicarbon and have this green colour and others don't.”

This comet was discovered in March 2022, and while it orbits the sun like earth, it takes thousands of years to make a single pass.

Comets like this may have been responsible for delivering water to early earth, and contain important clues about the chemistry of star and planet birth, Wiegert explains.

“We sometimes say that it's like a chocolate cake. There's a lot of ingredients that went into this chocolate cake. But the earth doesn't look very much like its ingredients anymore in the same way that a chocolate cake doesn't look like eggs or flour or sugar or anything like that.”

While the comet will be visible with the use of binoculars or small telescopes next week, Western’s Hume Croyn Memorial Observatory is holding a free open house Saturday, Jan. 28 that will reveal a much better image as long as the clouds stay away.

“If the weather does cooperate and we don't have too many clouds, we'll be pointing some telescopes at this comet. Fingers crossed that we get good weather,” says Wiegert

The comet will be most visible on Feb. 1, but will still be visible in the days before and after that point if clouds are persistent.