The Menace of the Asteroids. Part 1: The Risks

Artist’s impression of an asteroid approaching the Earth. Image Credit: Jeff Darling

Of the several hundred thousand asteroids known, about 9,000 are of the near-Earth variety, and of these more than 1,300 fall into the category known as potentially hazardous asteroids (PHAs). To qualify as a PHA, an asteroid must be able to come […]