Asteroids are rock remnants from the formation of our solar system. They may have brought the foundation of all life to Earth – but their impact today could have devastating consequences. However, humans are not helpless. “This is the only natural disaster for which we can account for before,” said Detlev Koschny, an asteroid expert at the European Space Agency (ESA) in Noordwijk, the Netherlands, on World Asteroid Day on June 30.
Bombing asteroids like in blockbuster movies is no longer just a fantasy. However, for some parts, there is a very large gap.
According to experts, asteroid impacts should be taken seriously – historical examples show power
According to the US space agency NASA, there are more than one million known asteroids in our solar system, of which more than 20,000 so-called Near Earth Objects (NEOs) transit in our orbit around Earth during their orbits. Two famous events demonstrate what such a cut can do: On June 30, 1908, a pressure wave from an asteroid explosion swept away – most likely – millions of trees over Tunguska in Siberia in an area roughly the size of the Saarland. In connection with this event, the United Nations later declared June 30 as International Asteroid Day.
In February 2013, an asteroid measuring 20 meters and traveling 66,000 kilometers per hour exploded over the city of Chelyabinsk. About 1,500 people were injured in the explosion, most of them hit by broken windows. Thousands of buildings were damaged.
Luminous objects constantly appear in the night sky – dust and tiny bits of rock from burning space in the atmosphere. “The total mass that reaches Earth is estimated at about 100 tonnes per day,” said Koschny. Large cuts are still a hazard. Warning protocols apply from a size of about 20 metres, said ESA’s Senior Asteroid Defense Coordinator Richard Moisel, whose team operates at Frascati near Rome.
Shooting as a possible defense option
The European Space Agency and NASA want to research asteroid bombing as a potential defense option. NASA’s Dart probe, which has already been launched, will collide with the smaller portion of the double asteroid in September and shift its orbit slightly around the larger asteroid. ESA’s “HERA” mission is scheduled to begin in 2024 and take measurements there.
“This so-called kinetic effect is the most promising technology because we already have it,” Moisel said. The action depends on the pre-alert time and the size of the object. “The final option is to use nuclear weapons, because that is the maximum amount of available energy that can be stored in an object in the shortest possible time.”
However, experts still see gaps in asteroid monitoring. According to Koschny and Moissl, observations are still being made almost exclusively from Earth. “In the future we will need space telescopes to have better early warning systems,” Moisel said. “We have to close the monitoring loophole.” Very large blocks are not the problem. “Things we all think we know,” said Koschny. “The current threat is the size range of 20 to 40 meters.” With an object 40 meters above the larger city, you have to evacuate – and within this size range, you only know a small percentage of potential candidates.
But people should not feel afraid and anxious at this time. “I can rule out threats to civilization today,” said Koschny. And Moissl also didn’t see anything serious coming down to Earth at the moment. “I can sleep well now.”
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