NASA collision with asteroid Dimorphos changed both its trajectory and shape

When NASA sent its DART spacecraft to slam into the asteroid Dimorphos in 2022, the U.S. space agency demonstrated that it was possible to change a celestial object's trajectory, if needed, to protect Earth. It turns out that this collision changed not only the asteroid's path but its shape as well.

The asteroid, which before the DART encounter looked like a ball that was a bit plump in the waist, now appears to be shaped more like a watermelon - or, technically, a triaxial ellipsoid, scientists said on Tuesday.

"The prevailing understanding is that Dimorphos is a loosely packed agglomeration of debris ranging from dust to gravel to boulders. Thus, its global strength is quite low, allowing deformation much more easily than for a solid monolithic body," said Steve Chesley, a senior research scientist at NASA's Jet Propulsion Laboratory (JPL) in California and a co-aut...