The constellation of the giraffe is not exactly small - in fact, it occupies more space in the sky than Orion or Andromeda.

And due to its location near the north celestial pole, it can also be observed in our latitudes at any time of the year.

Usually there is nothing to see there.

The brightest star in this constellation is fainter than the Andromeda galaxy.

Ulf von Rauchhaupt

Editor in the “Science” section of the Frankfurter Allgemeine Sunday newspaper.

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Nevertheless, many star lovers are directing their gaze to the giraffe these days, because since Sunday the first comet since the comet Neowise flew by in the summer of 2020, which is in principle visible to the naked eye from Earth, has been there.

On Wednesday, the new tail star will reach its closest point to Earth, after which it will steadily fade and likely never be seen again.

And then he's green too!

But first things first.

The comet's official name is C/2022 E3 (ZTF), which tells a lot about it to those who are privy to the naming conventions of comet scientists.

The letter C denotes comets that have not been seen in the inner planet region since all comets were systematically recorded 200 years ago, because they take longer to orbit the sun.

In this case, the object was probably last close to the sun around 50,000 years ago.

At first it was thought to be an asteroid

"2022 E3" encodes the time of its discovery: Since E is the fifth letter in the alphabet, it is the third object newly recorded in the fifth half of the month - i.e. the first half of March - of the year 2022.

Finally, the abbreviation ZTF stands for "Zwicky Transient Facility" in California, a special instrument for detecting transient, i.e. only temporarily appearing celestial phenomena, which was named after the Swiss-born American astronomer Fritz Zwicky (1898 to 1974).

The comet was discovered with this device on March 2, 2022, but initially thought to be an asteroid, i.e. a chunk of stone or metal.

At that point, however, he was still far out, somewhere between Jupiter's orbit and the asteroid belt.

Now comets consist largely of frozen gases, which only begin to evaporate when they are close to the sun – about twice the distance between the earth and the sun – and surround the solid core with a luminous cloud, the coma.

On January 12, C/2022 E3 reached its perihelion, ie its closest point to the Sun, just outside Earth's orbit.

What is so special about C/2022 E3 (ZTF)?

As far as is known so far, only its observability for people without large-caliber optics.

But let no one rejoice too soon.

Even where there is no February gray over the land, the comet watchers get in the way of the waxing moon, which becomes full moon four days after the next approach and only sets in the early morning hours.

You need eagle eyes or good binoculars

Above all, however, the comet will probably only just be visible to the naked eye at its closest position to the earth - there it is 109 times further away than the mean distance between Earth and the moon.

And that only for people with eagle eyes far away from any illuminated civilization.

Everyone else, in addition to a lot of patience and warm clothing, should bring good binoculars.

The chances are probably best again in the first half of February, when the comet's brightness has already decreased again, but the moon has narrowed again and rises later.

After February 4, the object will have left the star-poor giraffe and moved on to the more densely populated constellation Auriga and finally to Taurus.

In no case should one expect a show like that of Comet Hale-Bopp in 1997, the last really spectacular comet in the northern sky.

The green color of C/2022 E3 does not change that.

Because, firstly, it will hardly be visible to the naked eye, and secondly, it is not a unique selling point.

Other comets are also green, but this hue is found only in the coma, not in the object's tail.

The reason for this was only suspected for a long time and only empirically verified in 2021.

The green glow comes from a highly reactive substance made of diatomic carbon molecules.

This dicarbon is created by the interaction of the carbon monoxide contained in the comet gas with sunlight, in which it then fluoresces green.

However, dicarbon is also split by the sun's rays.

So if you miss C/2022 E3, don't worry about never seeing a green comet again.

But nobody will see this special one again afterwards, not even any of our distant descendants in 50,000 years.

Because according to everything that is known about the orbital ellipse of this comet, it will be stretched even further by the gravitational pull of Jupiter and Saturn, and the orbital period will thus be increased to millions of years.

It is also possible that he will leave the solar system completely and never return.