What are asteroids? How real is the threat of them causing extinction of life? What strategies have been developed to prevent such a catastrophe?
1. Asteroids are rocky
Asteroids are rocky, airless remnants of the solar system’s formation, orbiting mainly between Mars and Jupiter.
2. Near-Earth Objects (NEOs) follow orbits that
Near-Earth Objects (NEOs) follow orbits that bring them close to Earth; over 30,000 are currently tracked.
3. Most asteroids are small and harmless;
Most asteroids are small and harmless; daily impacts burn up in the atmosphere as shooting stars.
4. The Chicxulub impact wiped out dinosaurs
The Chicxulub impact wiped out dinosaurs 66 million years ago; extinction-scale impacts occur rarely, every hundred million years.
5. The threat of extinction is real
The threat of extinction is real but extremely low probability; regional impacts like Tunguska pose more immediate danger.
6. NASA’s Torino scale and Sentry system
NASA’s Torino scale and Sentry system assess collision risks; the 2029 Apophis flyby is being closely watched.
7. Planetary defence relies on deflection
Planetary defence relies on deflection, not destruction: kinetic impactors, gravity tractors, and nuclear options are studied.
8. NASA’s DART mission in 2022 successfully
NASA’s DART mission in 2022 successfully altered an asteroid’s orbit, validating the kinetic impactor strategy.
9. Early detection plus international cooperation
Early detection plus international cooperation, through UN-endorsed bodies like IAWN and SMPAG, is the best defence.
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