Earth’s night skies are receiving a surprise visitor this month.
Comet C/2022 E3 ZTF will make its closest approach to both Earth and the Sun in the coming weeks. The comet was first discovered in March 2022 by astronomers at the Zwicky Transient Facility, part of the California Institute of Technology’s Palomar Observatory, when it was 399 million miles (643 million kilometers) from the Sun inside the orbit of Jupiter. Since then, Comet C/2022 E3 ZTF has come very close to the Sun and Earth.
In fact, 11:00 PM EST on January 12 (0400 GMT on January 13), the comet will reach its closest approach to the Sun, which is known as perihelion. During this time, skywatchers may be able to see the comet with the naked eye, but if conditions are right, you should be able to spot it with binoculars or a telescope. Even if you don’t have the right conditions or optics to spot C/2022 E3 ZTF, you can watch a free live webcast of it here, courtesy of the Virtual Telescope Project. Website (opens in new tab) or its Youtube channel (opens in new tab),
Connected: Watch a comet make its closest approach in 50,000 years online next week
Comet C/2022 E3 ZTF has an orbital period of 50,000 years, which means it has not reached Earth since the Upper Paleolithic, a very early time. Homo sapiens and Neanderthal.
Not only hasn’t the comet been around for quite some time, it may also be the last time it heads our way. Its orbit is not closed, meaning that it does not return to the same angular position it started at. Due to its highly parabolic orbit, the C/2022 E3 ZTF will zoom out into deep space after its closest approach to Earth—perhaps never to return. Jessica Lee, an astronomer at the Royal Observatory Greenwich, told Newsweek (opens in new tab) that “predictions suggest that the orbit of this comet is so eccentric that it is no longer in orbit – so it is not going back at all and will just keep on going.”
Many astrophotographers around the world have already captured gorgeous images of the comet as it zips through the Solar System. Its coma, the cloud of gases and debris surrounding the comet’s nucleus, has a distinctive green color in photographs due to its chemical composition. The green color suggests the presence of diatomic carbon, or dicarbon, molecules that have two carbon atoms bonded together.
Comet C/2022 E3 ZTF can be observed throughout the month, not just at perihelion on January 12. After this close approach to the Sun, the comet will pass within 26 million miles (42 million km) of Earth on February 2.
Comet C/2022 E3 ZTF presents an excellent skywatching opportunity for skywatchers of all levels. If you don’t have the gear you need (or want!), be sure to peruse our guides to the best binoculars and best binoculars for viewing comets or other objects of interest in the sky. For the best comet images you can take, we have recommendations for the best cameras for astrophotography and the best lenses for astrophotography.