An asteroid has a slight chance of hitting Earth in 2032. Here's why the odds are a moving target, according to the astronomer who invented the scale used to measure such risks.

The odds that a potentially destructive asteroid will collide with Earth in 2032 have increased once again, NASA says, but the chance of an actual impact is still quite slim. NASA’s Asteroid Terrestrial-impact Last Alert System (ATLAS) first discovered the asteroid,