Astronomers are keeping a close eye on asteroid 1950 DA, which is expected to give Earth a close shave on March 16, 2880.
The strange asteroid -- essentially just a half-mile-wide collection of rubble rather than a rocky lump -- could cause tsunami-like waves if it were actually to collide with our planet. Fortunately, the chance of 1950 DA colliding with Earth has been pegged at just one in 4,000.
That's good news for our descendants, of course. Even better is this: astronomers at the University of Tennessee believe that 1950 DA might point the way to an effective means of eliminating other asteroids that do pose a meaningful threat to our planet.
In a new paper published in Nature on August 14, 2014, the astronomers theorize that the asteroid might be held together not by gravitational forces but by intermolecular bonding known as Van de Waals forces.
"We found that 1950 DA is rotating faster than the breakup limit for its density," lead researcher Dr. Ben Rozitis, a postdoctoral scholar at the university, said in a written statement. "So if just gravity were holding this rubble pile together, as is generally assumed, it would fly apart. Therefore, interparticle cohesive forces must be holding it together."
Astronomers have long suspected that these forces apply with smaller asteroids, but there has never been any opportunity to confirm past predictions. But now astronomers tracking near-Earth asteroids -- including space rocks similar to the one that crashed last year in Chelyabinsk, Russia -- could use lessons from 1950 DA to divert or destroy other space rocks, as long as they are held together by the same cohesive forces.
How would such a space rock be destroyed? "With such tenuous cohesive forces holding one of these asteroids together, a very small impulse may result in a complete disruption," Rozitis said in the statement.