Every day, smaller chunks from space burn up in the earth’s atmosphere, mostly unnoticed. However, if asteroids cross the earth’s orbit, they can become dangerous. Ten years ago, such a chunk of rock exploded over Chelyabinsk.
Ten years ago, a cosmic event shook the Russian city of Chelyabinsk in the Urals. An almost 20 meter large asteroid penetrates the earth’s atmosphere, pulls a tail behind it as it evaporates and explodes with a bright flash of light and a loud bang over the metropolis. The chunk of space comes without warning. Around 1,500 people were injured in the explosion on February 15, 2013 at around 9:20 a.m. local time, mostly from shattering window glass. Millions in damage occurs.
“Chelyabinsk is the largest impact event in the last 100 years and the most damaging in modern history,” says Richard Moissl, head of asteroid defense at the European Space Agency (ESA). For comparison: The asteroid known as the dinosaur killer a good 60 million years ago was twelve kilometers in size.
Many people panicked when Chelyabinsk exploded. “People could think otherwise, what kind of catastrophe is about to befall them,” says Moissl, who is based in Frescati near Rome with his team. “From our point of view, it came from the day side and we are blinded to a certain extent. We are disturbed by the sun and the scattered atmospheric light.”
With conventional technology or telescopes on Earth, there is a spot where it is very difficult to observe asteroids. If the arrival had been noticed early, people could have been warned. There would have been less panic and probably less damage, for example because windows could have been opened or secured as a precaution. The Chelyabinsk event was a wake-up call, says Moissl. Politicians and the public have become more aware of the potential dangers of asteroids. “It wasn’t taken as seriously then as it is now.”
According to the German Aerospace Center (DLR), most of the asteroids in our solar system are in a belt between Mars and Jupiter. However, they can also reach the inner solar system and thus also near the earth through different effects. So-called Near Earth Objects (NEO) are a latent threat to our planet. “Near-Earth objects are the potential assassins,” says DLR.
You need telescopes in space, says Moissl. “It’s our turn, we’ve now been given a mandate to study this mission and develop the technology.” One wants to search the region around the star for asteroids with an infrared space telescope in a point of equilibrium between the sun and the earth. “This is the focal point after the ‘Hera’ mission.”
The “Hera” mission is the second part of a joint project on asteroid defense together with the American space agency NASA. This shot the “Dart” probe at an asteroid that is harmless to Earth in order to slightly change the orbit of the chunk. When “Dart” hit the asteroid last October, NASA spoke of a “tipping point” for the protection of humanity.
“Hera” from Esa is to fly to the bombarded double asteroid Dimorphos in the coming year and collect data there from the beginning of 2027. The bombardment of asteroids and the change in flight direction is considered a way to distract celestial bodies on a collision course.
“In fact, we have already passed the mark of 31,000 asteroids that are close to Earth,” says Moissl. Potentially dangerous ones would be observed and their orbits calculated for the next 100 years. Accordingly, there is currently no dangerous asteroid on a collision course. However, the 370-meter-large asteroid Apophis will soon come very close to Earth. It will fly past our planet on Friday, April 13, 2029, just 31,000 kilometers away. Many satellites are further away. “The fewer observation gaps we have, the greater the likelihood of reacting,” says Moissl. But there is never 100% security.