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Asteroid 2024 YR4: A Close Call and a Wake-Up Call
ChileTuesday, March 11, 2025
The recent scare over asteroid 2024 YR4 highlighted the importance of planetary defense. Asteroids follow predictable orbits, and with enough data, scientists can calculate their paths with great precision. This allows us to predict potential impacts decades in advance. The key to planetary defense is not to destroy the asteroid, but to give it a slight nudge, altering its orbit just enough to avoid a collision. This is known as a "kinetic impactor" method. NASA's Double Asteroid Redirection Test (DART) successfully demonstrated this method in 2022. DART collided with the asteroid Dimorphos, shortening its orbit by 32 minutes. However, the collision also released a swarm of boulders, showing that there are still challenges to overcome.
The discovery of the Chicxulub crater in 1990 and the sight of the Shoemaker-Levy 9 comet hitting Jupiter in 1994 convinced Congress to take the threat of killer asteroids seriously. In 1998, Congress directed NASA to detect and catalog at least 90% of near-Earth objects (NEOs) that were more than a kilometer wide. NASA and its partners hit that goal with time to spare, and so in 2005, Congress directed the agency to identify at least 90% of all NEOs 140 meters or wider. Though over 18, 000 NEOs have been identified, about 40 every week, there may be a million or more out there. That mission continues.
The recent scare over asteroid 2024 YR4 was a wake-up call for planetary defense. It showed that our detection systems are working, but our defense systems still need improvement. The good news is that we have the technology and the knowledge to protect ourselves from this natural existential risk. With continued research and international collaboration, we can ensure that the next close call doesn't become a catastrophe.
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