A newly discovered green comet approaching Earth

To kick off 2023, the world will have an opportunity to view an amazing celestial sight in the sky as a newly discovered comet travels by our planet.

The green comet was first sighted early last year, according to NASA. It is thought to have traveled hundreds of billions of miles to reach the inner solar system.

Marc Weinberg, chief meteorologist at WDRB in Louisville, Kentucky, said the official name for the comet is Comet C/2022 E3 (ZTF). The ZTF refers to the where it was discovered – Zwicky Transient Facility – and the discovery was made in March 2022.

According to the National Science Foundation, the Zwicky Transient Facility is a powerful optical sky survey designed for fast, wide area coverage to identify rare, fast-varying astronomical sources. It employs a state-of-the-art camera with a 47 square degree field-of-view (the full moon is 0.2 square degrees) mounted on the Samuel Oschin 48-inch Schmidt telescope at Palomar Observatory in southern California.

Weinberg said he’s not aware of any change in the comet’s speed since it was discovered, but the appearance will change as it approaches the sun.

“The heat from the sun evaporates the comet’s core into dust and microparticles,” he said. “This means as the comet approaches the sun, normally, the tail becomes more and more visible.”

Weinberg said this is a long period comet from the Oort cloud. Being that it is a long period comet, no one currently alive has seen it.

“We know the Oort cloud to be the origin of many comets, and the Oort cloud is so big that it surrounds all objects in our solar system,” he said. “Green comets are somewhat rare. The last to pass by Earth was Ison in 2013.”

Weinberg said the best viewing is going to be Feb. 2, but any clear night is worth an attempt.

Heather Trandal, an earth and space science teacher at Seymour High School, said when she teaches to the kids about comets, she tells them what their textbook says: A comet is a small eccentrically orbiting body made of rock and ice which have one or more tails that point away from the sun (eccentricity defines the shape of an object’s elliptical orbit).

Trandal said Comet C/2022 E3 and Halley’s Comet are both comets, but their behavior is different.

“Halley’s Comet is a periodic comet, meaning it travels on its orbital path in a regular fashion and it’s predictable and can show up near Earth every 75 to 79 years,” she said. “The green comet is different because it doesn’t come near Earth on a regular basis. Also, the green comet has its green hue, which makes it unique. The green glow around some comets comes from the breakdown of a reactive molecule called dicarbon (C2).”

Trandal said this particular comet last visited the inner solar system around 50,000 years ago. Roughly one comet per year is visible to the naked eye, though many of those are faint and rather unremarkable.

It’s possible the current comet could pass by Earth again, but not for at least a million years and it might never return, she said.

Photos of the comet can be seen on the NASA website. One taken last Wednesday was from Dan Bartlett of California.

He said the photo was taken from outside a cabin where he has equipment set up at June Lake, about 30 miles outside of Yosemite Village in California.

“The photo from Jan. 18 was taken on a blistery cold day of -17C where nothing seemed to be working right and even the computer mouse died,” Bartlett said. “The photos you’re seeing online haven’t been photoshopped, but the images have been stretched, saturated and brightened because you just can’t snap a good picture in the dark, even through telescopes.”

He was a high school teacher for more than 30 years and retired a year ago from a school in Manhattan Beach, California, where he taught science the last five years and astrophysics.

“I loved it and the kids were great, if you can imagine taking a class where you get to go out and look at the stars from using telescopes, using cameras and simulations,” Bartlett said. “It turned a lot of kids into believers that there’s more to life than what’s around them, so that was kind of neat.”

Honeytown resident Forrest Willey of NaturalScape Services Inc. in Cortland also is an astrophotographer and owns Cortland Astronomy.

Willey said he has not tried to take a photo of the Comet C/2022 E3 (ZTF) yet since the visual magnitude on it right now is low.

“It might show up with binoculars in clear sight, but the best way to view it would be through long exposure photography, and even then, it’s not going to have that great big dramatic tail associated with comets,” he said. “If you’ve got a telescope and the right kind of properly calibrated mount, you might be able to get more detail out of it.”

Willey said to get any dramatic comet photos, the comet needs to be pretty bright, and it has to have a great tail on it.

“I think this comet will eventually get a decent tail, but it’s impossible to say with any type of certainly what’s going to happen,” he said. “Comets are kind of like cats. They have tails and they do what they want. I know in February, it’s going to get brighter, and you might be able to see it with the naked eye, and it will be near the North Star at that point.”

He said getting away from city lights might help people get a better look at the comet.

As an astrophotographer, Willey has taken photos of past comets. The last big one was C/2020F3 NEOWISE in 2020.

“It was appropriate because 2020 was sort of a dumpster fire, and historically speaking, comets were looked at as a bad omen,” he said. “We get comets every year, but it just doesn’t happen very often that they’re breaking the visual magnitude barrier.”

He said planetarium apps for cellphones are a great way of tracking the comet in real time. He purchased and uses the SkySafari app, which helps identify stars, planets and constellations by holding the user’s phone up to the sky. As you move the phone around, the sky chart follows. There are other similar apps available that are free.

“Anyone wanting to take photos of the comet, I’d suggest using a fairly wide angle lens around 15 to 24 millimeters, and you’ll want a fairly low F number on it, from F1.4 to F.4 but preferably F2.8,” Willey explained. “The ISO should be set between 1,600 to 6,400 and exposure time should be from 20 to 30 seconds and shoot off of a tripod or some sort of rest.”

Willey’s photos can be viewed and/or purchased on his website, forrestwilley.com.