Comet 2022 E3 (ZTF), better known as the “green comet”, will pass close to Earth next week after 50,000 years of its last approach.

The comet has a long orbit that takes it from the outer reaches of the Solar System towards the Sun for thousands of years and will now be closest to Earth on February 1, at a distance of 42 million kilometers which is equivalent to 109 times the distance average from Earth to the Moon. In the southern hemisphere it will only be visible on February 4.

On the days around its closest approach, it is expected to become brighter and easier to see with the naked eye or with binoculars. “We don’t know how bright it’s going to be, predictions say it’s going to be visible to the naked eye, but no one knows for sure. We are going to see at the end of the month when it reaches its maximum approximation”, said Beatriz García, doctor in Astronomy and principal investigator of the Conicet.

And he pointed out: “The predictions are that it could reach an integrated brightness of magnitude 5, in which case it would be seen because it is a magnitude that the human eye can detect.”

“It will be seen looking north, at sunset and very late at night is when one expects to see it best. The problem is that there is also going to be a crescent Moon and that can become an obstacle”, pointed out the specialist in astrophysics.

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Comet 2022 E3 (ZTF) was discovered in early March 2022 by the survey camera of the Zwicky Transient Facility program at the Palomar Observatory in California, United States.

Regarding why it was dubbed the “green comet”, García explained that it has to do with its chemical composition: “Although the comet is mainly water ice, it is mixed with material from the original nebula when the Solar System was formed and that material is released when approaching the Sun”.

“In the photos you can see that the coma, which surrounds the nucleus of the comet, is very green and that color is attributed to the dicarbon monoxide molecule,” said the researcher, adding that as the comet approaches the sun, its temperature increases and its brightness increases because the ice goes directly into a gaseous state.

And he continued: “The gas and dust that is released in this transformation process are ejected against the Sun and form the tail of water vapor that is quite bright.”

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The comet takes about 50,000 years to orbit the Sun, so the last beings to see it, if they could, were the Neanderthals.

“Now it is coming back. That means that in the past it had a closed orbit, but now the orbit has changed due to gravitational disturbances. The orbit became open, which implies that the comment is going to move away from the Solar System forever”, García added.

On the other hand, the specialist indicated that the comet’s passage has “no effect on the earth or on the solar system” and specified that “they are small and interesting objects that attract attention if they can be observed with the naked eye.”

As a recommendation to try to contemplate the comet, the researcher suggested “looking for binoculars and a well-cleared place where you can see towards the north cardinal point.”

“At nightfall you have to try to distinguish an object that is like a little cloud,” said García and concluded: “Hopefully we can detect it with the naked eye, the issue is that they are unpredictable objects.”

Source: Telam