How To See the Green Comet That’s Heading Our Way

Renee Hanlon

January 10, 2023 at 11:37 AM·4 min read

Get ready to check out the once-in-50,000-years phenomenon.

A comet with a bright green nucleus and long faint tail will be visible with a telescope or likely just with binoculars starting on January 12. This hasn't happened in 50,000 years. This recently discovered green comet, called C/2022 E3 (ZTF), is passing through our inner solar system now. The comet was first sighted in space in March of last year when it was already inside the orbit of Jupiter.

According to NASA, viewers in the Northern Hemisphere should begin to see the comet in the morning sky as it makes its closest approach to the sun on January 12. Then, the comet will be closest to the earth on February 2, when it will be visible in the Southern Hemisphere.

Although comets are quite unpredictable, if this one remains at its current level of brightness, it may even be able to be seen with the naked eye, especially in dark skies this month. It should be easy to spot the comet from a star because of the long tail of dust particles. However, conditions have to be right—meaning a clear sky is ideal.

What Is a Green Comet?

A comet is made up of clumps of frozen gas, rock and dust. When a comet gets close to the sun, it heats up and spews the gases and dust into a glowing mass that looks like a coma with a long tail. According to the study of chemist Gerhard Herzberg, the fact that this comet is green is because it has the presence of compounds like diatomic carbon and cyanogen that make it look green.

How the Comet Was Discovered

Back on March 2, 2022, astronomers Frank Masci and Bryce Bolin first spotted an object that they initially identified as an asteroid. It appeared very dim at the time. With later observations, it became clear that it was a comet because it had a very tightly condensed coma. When first discovered, the comet was situated 399 million miles (643 million km) from the sun, or just inside the orbit of the planet Jupiter.

How Did the Comet Get Its Name?

Comets have more of a code designation than an actual name. According to SPACE, the comet was the third such object discovered in the fifth half-month (A, B, C, D, E) of the year, so it received the designation C/2022 E3 (ZTF).

What Is Special About This Green Comet?

The fact that this is the first time this comet has been seen in 50,000 years makes it a rare occurrence. And, this may be the last time that we ever see this comet again. Astronomers at SPACE, the comet is on a parabolic orbit, which means that it is not a closed orbit. It will return into deep space and never return.

How Likely Is It That The Comet Will Be Easy To See?

Depending on where you are, actually seeing the comet could be difficult. Although there is a better chance of seeing it when it's closest to the sun on January 12, as the comet gets closer to Earth it will become rather larger, more angular and more diffused. It won't be sharp and distinct like a star. Instead, it will be spreading its light over a large area.