Rare Green Comet Makes Last Pass By Earth

(KNSI) – A rare green comet will be visible in the night sky for the next few weeks.

Called C/2022 E3 (ZTF), the name signifies it was discovered last year in early March by an observatory in California. The comet’s only other appearance near Earth was 50,000 years ago.

A comet is a mixture of dust and ice. Saint Cloud State University Assistant Professor of Physics and Astronomy Hridaya Shah says when it nears our sun, an effect similar to that of dry ice gives it a tail of vapor.

“We know if you melt ice, it converts into water, and if you keep on heating that water it converts into steam. Sublimation is a process in which the liquid state of ice is completely skipped over. The solid completely gets converted into vapor.”

Also mixed in is diatomic carbon, which gives the comet its distinctive green hue. It is visible with a telescope or binoculars. The best view will be on February 2nd, weather permitting.

Shah says mathematical formulas can be used to figure out its past trajectory and where it is headed. Shah says this will be the last time the green comet is near Earth.

“What the “C/” means is that it’s a non-periodic comet. This is the last time we are going to see this. It’s not going to pay us a visit after 50,000 years from now.”

Earth is not at risk of being hit by the comet, it will be millions of miles away at its closest point. The comet originated in the Oort Cloud, which rings our solar system for trillions of miles.

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