Asteroid deflection could lead to collision with Earth
Trying to knock an asteroid off course to protect Earth sounds cool, but it's trickier than you'd think.
A team from the University of Illinois found that if we're not careful, deflection attempts could accidentally push an asteroid into a "gravitational keyhole"—a tiny spot in space that could set it on a collision path with Earth later.
NASA's DART mission pulled off a successful test back in 2022, but future missions need extra precision.
Probability maps for safer impact zones
To help avoid these risks, researchers led by Rahil Makadia have created "probability maps" that show which impact zones on asteroids are safest and steer clear of those dangerous keyholes.
Making these maps requires detailed info about each asteroid—like its shape and spin—which is best gathered by space missions, though telescopes can give us quick data in a pinch.
The European Space Agency's Hera mission is set to visit the DART site in December 2026 to improve these techniques even more, making sure future planetary defense efforts stay smart and accurate.