Humans develop strategies against asteroid threat from space
A new Der Spiegel podcast explains how humanity can deflect asteroids heading toward Earth. Experts discuss successful missions like DART and future plans. The probability of such impacts is low, but the consequences would be devastating.
The podcast 'Danger from Space: How Humans Stop Asteroids' sheds light on the threat from near-Earth objects (NEOs). According to experts like astrophysicist Martin Elvis from Harvard University, there are about 25,000 asteroids larger than 140 meters that could endanger Earth. An impact from a 1-kilometer asteroid could trigger global catastrophes, similar to the dinosaur extinction 66 million years ago.
NASA's DART (Double Asteroid Redirection Test) mission in 2022 demonstrated for the first time the effectiveness of the kinetic impact method. The spacecraft crashed into the moon Dimorphos of asteroid Didymos, altering its orbit by 32 minutes – a success that confirmed the deflection technique. 'This was a milestone,' said DART leader Nancy Chabba in a NASA press conference.
Other methods include using spacecraft for gentle deflection via gravity or, in extreme cases, nuclear explosions near the object. The ESA plans the Hera mission in 2024 as a follow-up to DART to analyze the effects more precisely.
Experts emphasize that asteroid detection must improve. NASA's Near-Earth Object Program has cataloged 95 percent of large objects so far, but smaller ones like the 2013 Chelyabinsk meteorite, which injured 1,500 people, remain a hazard. The podcast warns: 'We are better prepared than ever before, but not safe enough yet,' quoting planetary scientist Alan Harris.
Background: Asteroid impacts are rare, with a probability of 1 in 300,000 per year for a major event. Nevertheless, the International Asteroid Warning Network (IAWN) drives global cooperation. The podcast, hosted by Ranga Yogeshwar, makes these complex topics accessible and underscores the need for ongoing research.