PressSplit
Photographers like Ralf Gerstheimer, who managed to capture this image of a meteor in the constellation Perseus in Dörnberg, should try long exposures with the shortest possible focal length, says Dr. Susanne Hüttemeister. © Photo: Ralf Gerstheimer
In August you can watch the Perseid spectacle in the night sky. Many shooting stars are visible to the naked eye.
Altena – Dr. Susanne Hüttemeister is a child of Altena, professor of astronomy at the Ruhr University and director of the Zeiss Planetarium Bochum. And of course she knows exactly how to best enjoy the Perseid spectacle in the night sky in August – “With the naked eye!” advises the expert on our home, the Milky Way.
Shooting stars: When the Perseids can be seen “with the naked eye”
“Around Altena, you should definitely drive out of the valleys to a height with as much clear horizon as possible in order to see as much of the sky as possible. Perhaps Wixberg or Großendrescheid are possible – but not in the forest or near street lamps,” explains Dr. Susanne Hüttemeister.
Since the observation area should be as dark as possible, inner cities are not suitable. At most, only the brightest meteors could be seen there. The rule is: the darker the sky, the better. The Sauerland, rural areas in Münsterland or the Eifel are therefore not bad starting points. If you want to watch from home, you should choose a place that is shielded from light. At the very least, the band of the Milky Way should be faintly visible, which is always a strong quality criterion for dark skies.
Enchanting comet dust: When the shooting stars are best seen
“The Perseids light up everywhere in the sky, but it is good if you can see the radiant, i.e. (around midnight) you have a clear view towards the east, where Perseus is. The right observation device is the naked eye. Binoculars have a field of view that is far too small to be useful,” explains Dr. Susanne Hüttemeister.
The astronomer, who grew up in Altena, also has a tip for photographers: They should try long exposures with the shortest possible focal length, so that as much of the sky as possible is in the field of view of their camera. “Long exposures are recommended to increase the chance of catching a meteor, as there are often several minutes between individual shooting stars. How long you can expose depends on the brightness of the sky – in a bright city sky, the possible time is of course shorter than in a dark sky.” Since Altena is a small town and is exposed to significantly less light pollution, the chances of seeing something are much better here.
But what is the Perseids all about? Dr. Susanne Hüttemeister knows this too: “August is considered the ‘shooting star month’, because the Perseids, probably the most well-known meteor shower of the year, are active in the middle of the month. Their maximum is expected this year on August 12th around midday. It will of course be light then, but the nights from August 11th to 12th as well as from August 12th to 13th are suitable for observation. Some shooting stars can also be expected on the nights a little further away from the maximum.”
Perseid shower in August: “20 or 30 shooting stars in one hour”
However, Dr. Hüttemeister would also like to point out that expectations may be too high and avoid disappointment, as conditions are not always favorable: “You often read that on the night of the maximum, more than 100 shooting stars or meteors – which is the same thing – can be seen per hour. But this information should not raise expectations that are too high. It is based on assumptions that are almost never fulfilled: the sky must be perfectly dark, no obstacle must block the view and the meteors must come from the zenith, i.e. the highest point in the celestial sphere. Under real conditions, you can be happy if you see 20 or 30 shooting stars in an hour.”
In addition, most shooting stars are not very bright. “Moonlight plays a major role here – during a full moon, only a few particularly bright meteors stand out against the brightened sky. This year, August 12th is a waxing crescent moon. On the evening of August 11th, the moon sets over Bochum at 11:02 p.m., and the next night it disappears below the horizon at 11:19 p.m.”
Dr. Susanne Hüttemeister, director of the Planetarium Bochum. © private
You can’t start observing earlier anyway, because it has to get dark first and the point from which the shooting stars appear to be emitted has to have climbed above the horizon. “This point, called the radiant, is – as the name suggests – in the constellation Perseus, north of Taurus, where Jupiter and Mars are found. The best time to observe the Perseids is after midnight – and it can be wonderfully combined with a view of the two planets,” says the professor.
But what exactly is a shooting star?
“It has nothing to do with stars, or even those that fall from the sky. Rather, it is small grains of dust that a comet has left behind on its orbit around the sun. The Earth passes through this band of dust at the same time every year. In doing so, it collides with the grains of dust, which in the case of the Perseids enter the Earth’s atmosphere at a speed of around 60 kilometers per second. At an altitude of around 80 kilometers, they burn up and stimulate the air particles to glow. What flies across the sky in seconds is therefore created by heated air,” explains the astronomer.
The comet that causes the shooting stars has literally disappeared a long time ago: it is in a completely different place on its orbit. In the case of the Perseids, it is named “Swift-Tuttle” after its discoverers and will not be near Earth again until 2126. Its legacy, however, delights entire generations of human children and makes them look up to the sky every year. “Astronomers like to joke: Here they come again! But I will also look up to the sky, precisely because the visibility conditions are different every year. I still enjoy the Perseids,” explains Dr. Susanne Hüttemeister with a laugh.
A visit to the planetarium is worthwhile
A look at the program of the Zeiss Planetarium Bochum, which she manages, confirms this: the endless possibilities that the universe offers are also reflected in the series of events at the science and culture center. “We show the greatest!” advertises the institution, and all employees bring a lot of fun to space adventures for children and celestial phenomena for adults. A visit is definitely worth it. The events calendar can be viewed at www.planetarium-bochum.de.
