What's holding 'gravity-defying' near-Earth asteroid together revealed

A new study has helped scientists uncover the forces that are keeping the near-Earth asteroid from breaking apart and potentially protecting Earth from a massive asteroid impact.

Researchers at UT studied near-Earth asteroid 1950 DA and discovered that the body, which was rotating faster than the breakup limit for its density that it defies gravity, has been held together by interparticle cohesive forces, called van der Waals, never before detected on an asteroid.

In fact, the rotation has been so fast that at its equator, 1950 DA effectively experiences negative gravity. If astronauts were to attempt to stand on this surface, they would fly off into space unless they were somehow anchored. The finding provided important information for efforts aimed at stopping an asteroid from crashing into Earth.

This research revealed some potential techniques, such as a kinetic impactor which would deploy a massive object on a collision course with the asteroid, could exacerbate the impact's effects. The findings also have implications for space exploration.

Ben Rozitis, a postdoctoral researcher, said that with such tenuous cohesive forces holding one of these asteroids together, a very small impulse may result in a complete disruption.

The study is published in the science journal Nature.