Status: 25/09/2023, 19:02 p.m.
By: Tanja Banner
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The asteroid "Bennu" is number 1 on NASA's risk list. But it does not pose an acute danger. (archive image) © IMAGO/piemags
The asteroid "Bennu" is currently of particular interest to scientists. But there is also a small risk that it will hit Earth in the future.
Munich – The asteroid "(101955) Bennu" is currently in the focus of science, because on Sunday (24 September) the US space agency Nasa wants to bring a soil sample from this asteroid to Earth with the help of the space probe "Osiris-Rex". Then the focus will be on the exploration of the asteroid rock. But "Bennu" is not just any asteroid – it is the most dangerous asteroid NASA currently knows.
The asteroid, which is named after the ancient Egyptian goddess of the dead, Benu, is at the top of Nasa's risk list. With a diameter of about 500 meters and an orbit around the sun that lasts only 437 days, "Bennu" may one day be dangerous for Earth. The Nasa risk list mentions a total of 2178 possible dates for the years 2290 to 157 when the asteroid could hit Earth.
Asteroid "Bennu" could hit Earth in 2182
But no one has to worry about the asteroid "Bennu": Although there is a chance of about 2300 in 1 that the asteroid will hit the Earth by the year 1750, this value is vanishingly small on closer inspection. Nasa has identified September 24, 2182 as the date on which there is the greatest chance that the asteroid "Bennu" will hit Earth. On this day, according to the authority, the probability of impact is 0.037 percent – which is also no cause for concern.
If, despite all its improbability, the asteroid were to hit the Earth, the impact on the affected region would be enormous: a crater with a diameter of more than six kilometers would be created and the effects would still be clearly felt outside this crater. However, an impact of "Bennu" would not be comparable to the asteroid that caused the dinosaurs and numerous other animal species to become extinct 66 million years ago. This celestial body was estimated to have a diameter of 14 kilometers.
NASA probe "Osiris-Rex" brings soil sample from asteroid "Bennu" to Earth
The asteroid "Bennu" is therefore dangerous – but was not chosen for the sample retrieval mission "Osiris-Rex" for this reason. According to Nasa, his choice has more to do with the fact that the asteroid is relatively close to Earth and is the right size. The researchers hope to use the collected asteroid material to learn more about the past of the solar system, because "Bennu" is a remnant of the turbulent time in which the solar system was formed.
| Name: | (101955) Bennu (1999 RQ36) |
|---|---|
| Type: | Apollo asteroid |
| Discovery: | September 11, 1999 |
| Discoverer: | LINEAR project |
| Orbit around the Sun: | 437 days |
| Diameter: | Just under 500 meters |
Some researchers also call asteroids "time capsules from the early days of the solar system" because they still contain the material from that time and have been preserved in the vacuum of space. Scientists also want to use "Bennu" to find out what role asteroids may have played in the emergence of life on Earth.
How to protect the Earth from asteroids?
Of course, science also wants to find out more about asteroids through the exploration of "Bennu". How are they composed, how do they behave and, in the worst case, how can the earth be protected from them? In this context, "Bennu" focuses primarily on the so-called "Jarkowski effect". When sunlight hits the celestial body, the non-uniform surface of the asteroid is heated differently – this phenomenon can influence the trajectory of the asteroid and should be better included in calculations of the trajectory in the future. (tab)
