Since the summer of last year, astronomers have been looking forward to the comet 12P Pons-Brooks. Not only because the comet`s tail still looked like the starship Enterprise in the summer of 2023, but because it may even be visible to the naked eye in the spring of 2024.

But what are comets?

Among astronomers, they are often referred to as “dirty snowballs”. This is quite justified. Comets are larger chunks (a few kilometers in diameter) of rock, dust and ice. They formed during the period when the solar system was very young and just formed. That‚s why they‚re so interesting for astronomy. When it comes to comets, you have to diffierentiate between several types. One type is the short-periodic comets. These take less than 200 years to orbit the sun. Comet 12P Pons-Brooks, which is the subject of this article, is a short-period comet. He‚ll be back to inner solar system again in 71 years. Furthermore, a distinction is made between the long-periods, which have an orbital period of more than 200 years, and the non-periodic ones. These pass the sun only once on parabolic or hyperbolic orbits.

Visibility and comet tail

The comet is currently a little too dark to be seen with the naked eye, but forecasts give hope: The comet could reach the 4th to 5th magnitude at the end of March. If this is the case, the comet could be detected with the naked eye under dark skies and good orientation in the night sky. Definitely binoculars or a telescope would also be worthwhile. The best time to observe the comet with the mentioned aids is from 24. 03.2024 until 05. 04.2024. Unfortunately, this is only a fairly short period of time, so you have to hope for good weather. At this time, the comet will be in the evening western sky low in the constellation of Aries in Germany. For accurate tracking of the comet, I recommend the apps „Stellarium“ and „SkySafari„, which are free in the basic version for the mobile phone. In a telescope, the comet currently shows a beautiful tail of ions and dust.

These tails, typical for comets, are formed when a comet approaches the Sun, warms up and loses the matter that forms a tail. The comet also shows a greenish-blue glow. This is due to the presence of dicarbon compounds in the coma (bright dust region around the nucleus of the comet). If the comet comes close enough to the Sun, they are ionized by the Sun`s UV radiation and thus stimulated to a green-blue glow. This colourful glow could already be seen in almost every comet that visits the inner solar system.