The hustle and bustle of our solar system
Tuesday, July 31, 2012 - 09:01
in Astronomy & Space
(Phys.org) -- This diagram illustrates the differences between orbits of a typical near-Earth asteroid (blue) and a potentially hazardous asteroid, or PHA (orange). PHAs are a subset of the near-Earth asteroids (NEAs) and have the closest orbits to Earth's orbit, coming within 5 million miles (about 8 million kilometers). They also are large enough to survive passage through Earth's atmosphere and cause damage on a regional, or greater, scale.