An incredible sight is expected to be flying through the sky Feb. 1 and Feb. 2: a rare green comet.
Cornell astronomy professor Philip Nicholson said there are two main types of comets when it comes to their orbits, predictable ones that tend to come on a schedule and new comets, or long-period comets. He calls those “messengers from the outer solar system.”
“These are coming in from a very distant reservoir, or collection of icy objects, way beyond the planets, way out beyond the orbits of Neptune and Pluto," said Nicholson.
Nicholson’s eyes will be on the skies this week looking for one of those long-period comets: Comet 2022 E3 (ZTF). The green comet is expected to get about 42 million kilometers from Earth, giving stargazers a chance to look.
Some scientists estimate its last visit to Earth was 50,000 years ago, but Nicholson thinks that’s just a guess.
"Often, on their way into the solar system or on their way back out again, comets have an encounter, or a reasonably close encounter with one of the giant planets, and that can be enough to change their orbit," he said.
If you’d like to see the comet, Nicholson recommends trying binoculars when the skies are clear and the moon isn’t too bright.
"The place to look is up in the sky in the north between the Big Dipper and the Pole Star, and then look for something that has a faint tail on it like you'd expect a comet to be. But it will not be blindingly bright. It will be a faint thing," he said.
While it’s impossible to make a definite prediction, Nicholson believes this will be the comet’s last trip near Earth. Its current orbit will give it enough energy to escape from the sun and wander off into interstellar space.
