Planetary defense: its proven! We are now able to deflect small moons!

The NASA DART mission has proven our ability to deflect asteroids to protect Earth from potential collisions. A recent discovery shows that by hitting a moon of an asteroid, we can modify the trajectory of the entire space system.

In September 2022, NASA’s DART probe intentionally collided with the small moon Dimorphos. The objective was clear: to test our ability to deflect an asteroid to protect Earth from an impact. The success is total, as the orbit of this 160-meter moon was shortened by 33 minutes.

IS 33 MINUTES A LOT?

This is a result much more significant than what scientists initially hoped for. But the surprise does not stop there, as a new study reveals an even broader effect. By hitting the small moon, the probe also altered the course of the main asteroid, Didymos. Its 770-day orbit around the sun was reduced by 0.15 seconds, a scientific first. This discovery shows that we can change the trajectory of a giant asteroid by targeting its satellite. This adds a valuable strategic option to effectively respond to potential space threats.

AND THEN?

To go further, a new European mission called Hera will take over soon. It will join the duo of asteroids to precisely analyze the consequences of the 2022 impact. Two mini-satellites, Juventus and Milani, will be deployed to scrutinize every detail of the collision. The CNES in Toulouse will play a key role in controlling their trajectories and scientific instruments.

For more information, by Olivier Sanguy from La Cité de l’Espace.