New tool to improve planetary defense


A method for mapping an asteroid’s interior structure, or density distribution, may improve the target of future planetary defense missions targeting asteroids.

Such mapping is done based on how the asteroid’s spin changes as it approaches more massive objects like Earth, as explained by MIT researchers who have designed the tool.

Knowing how density is distributed within an asteroid could help scientists plan the most effective defense. For example, if an asteroid were made of relatively light and uniform matter, a DART-like spaceship it might aim differently than if it were deflecting an asteroid with a denser, less balanced interior.

“If you know the density distribution of the asteroid, you could hit it in the right place to make it fly away,” he says. it’s a statement Jack Dinsmore, who developed the new asteroid mapping technique as a physics undergraduate student at MIT.

The team is eager to apply the method to Apophis, a near-Earth asteroid estimated to pose a significant hazard if it were to impact. Scientists have ruled out the likelihood of a collision during upcoming Apophis flybys for at least a century. Beyond that, your forecasts become hazy.

“Apophis will pass close to Earth in 2029, and scientists have cleared it for their next encounters, but we can’t clear it forever,” says Dinsmore, who is now a graduate student at Stanford University. “So it’s good to understand the nature of this particular asteroid, because if we ever need to redirect it, it’s important to understand what it’s made of.”

Dinsmore and Julien de Wit, an assistant professor in MIT’s Department of Earth, Atmospheric, and Planetary Sciences (EAPS), detail their new method in a study that appears in Monthly Notices of the Royal Astronomical Society.