Green Comet Set for 'Cosmic Meeting' With Mars in Sky This Week: Watch Live

The green comet C/2022 E3 (ZTF) is set for a "cosmic meeting" with Mars in the sky this week—and here's how you can watch the celestial event live from the comfort of your own home.

The comet was discovered by the Zwicky Transient Facility (ZTF)—an astronomical survey conducted by the Palomar Observatory, near San Diego in California—on March 2, 2022.

The comet C/2022 E3 (ZTF) and Mars
Split image showing the comet C/2022 E3 (ZTF) and a stock illustration of the planet Mars. The image of the comet was captured on January 29, 2023 by astronomer Gianluca Masi with the Virtual Telescope Project. Gianluca Masi/The Virtual Telescope Project/iStock

Comets are astronomical objects made up of frozen gases, dust and rock that orbit the sun. Sometimes referred to as "cosmic snowballs," these objects are blasted with increasing amounts of radiation as they approach our star, releasing gases and debris.

This process forms a glowing atmosphere around the comet's nucleus, known as a coma—which, in the case of C/2022 E3 (ZTF), appears green. There are also two vast tails of gas and dust.

The cosmic snowball has already made its closest approach to both the sun and Earth—on January 12 and February 1, 2023, respectively. It is now speeding away from our planet, perhaps never to return.

By around February 11, the comet will pass through the plane of the solar system in which the orbits of the planets lie. Specifically, C/2022 E3 (ZTF) will fly in between the orbits of Earth and Mars.

Because of the way in which the two planets will be aligned on this date, the comet— which may have last visited the inner solar system some 50,000 years ago—will be visible in the same patch of sky as Mars.

The comet and the red planet will be within just one degree of each other in the sky during this cosmic meeting. This means the apparent distance between the two objects will be roughly equivalent to two full moons placed next to each other.

But even though the comet and Mars will appear to be close from the perspective of the Earth, they will be around 50 million miles apart at this point, astronomer Gianluca Masi with the Virtual Telescope Project (VTP) told Newsweek.

At the time of the encounter, the red planet will be around 100 times brighter than C/2022 E3 (ZTF), Masi said.

While the comet has been spotted with the naked eye by some observers on Earth under ideal conditions, it is unlikely that this will be possible by February 11, Masi added. The comet will move further and further away from us, gradually becoming fainter in the sky.

So, you will likely need binoculars or a telescope—as well as a stargazing app—to catch a glimpse of it at this time.

Alternatively, the VTP will be hosting a live stream that will image and share this cosmic meeting. This is a service provided by the Bellatrix Astronomical Observatory in Ceccano, Italy, that operates and provides access to robotic, remotely operated telescopes.

The live feed is scheduled to begin at 2 p.m. ET or 11 a.m. PT on Saturday, February 11.

As C/2022 E3 (ZTF) speeds away from the inner solar system, there is some uncertainty about what will happen next. Astronomers have said it is possible the comet will never return. Even it does, this will not likely occur for millions of years.

"It's not a straightforward scenario," Diana Hannikainen, observing editor of Sky & Telescope magazine, told Newsweek. "It all depends on how much C/2022 E3's speed will be affected during this latest visit to the solar system.

"Astronomers think it's likely that at least Jupiter's gravity has already influenced the comet's path somewhat on the way in, nudging it into a much-longer orbit. That's where the million-plus-year estimate comes into play," she said.

"However, if its orbit is perturbed enough by the planets' and the sun's gravity, the comet will embark on a hyperbolic trajectory that will fling it out of the solar system, never to return."