by Alina Ferguson
A comet is a ball of ice which burns up when it passes the sun. That burn-off is what is seen by the human eye. On February 1, the green comet known as C/2022 E3 (ZTF) was at its closest and able to be seen by the naked eye, though it was 26 million miles from Earth.
Though it was visible in the Northern Hemisphere, the conditions in Humboldt were not optimal for viewing. Many may have had a hard time seeing this comet, referred to as C/2022, due to fog and pollution in the sky. For those who missed it on Feb. 1, it was still visible by telescope or binoculars Feb. 2.
Comets have an elliptical orbit. They spin close to the sun and then away from it, interacting with the gravity of other objects along the way. When they pass by the sun, they sometimes become visible from Earth. What we see is the comet releasing gasses.
Comets are from the outer solar system and they spend most of their lives very far from the sun. Tyler Mitchell, a physics professor at Cal Poly Humboldt, refers to them as, “little time capsules of frozen ices and a variety of different types of dust, like carbon and silicates.”
C/2022 is a green comet. “The color comes from two carbon atoms stuck together,” said Mitchell. “The tails of most comets are yellow.”
To Tanner B. Hooven, a student and member of the Cal Poly Humboldt Astronomy Club, C/2022 is a reminder of Earth’s past. We are the first people since the recording of time to see this comet.
“This comet is special because of its orbital period, or the time it takes to make one full journey around the sun, is approximately 50,000 years according to Nasa’s Jet Propulsion Laboratory,” Hooven said. “The last time this comet approached its perigee was at a time in which Neanderthals were still roaming the earth.”
Comets are sometimes called “dirty ice balls”, though they should be referred to as an icy dirt ball, given their respective ratios. Comets can become asteroids, which are referred to as “dormant comets.”
When identifying comets, or asteroids, astronomers look for what is essentially a “photobomb” and streak that was not previously there, or a bright shining star that was not before visible, according to Mitchell.
This comet is currently on its way out of the inner solar system. It will take months for it to fade from our view.
“It is likely this comet will continue to orbit the sun for millions of years until the off-gassing process subsides due to a lack of ice left in the comet,” Hooven said.