Some asteroids do have the potential to strike Earth.

Raymond Bambery is Principal Investigator of NASA’s Near-Earth Asteroid Tracking, or NEAT. He said well over 100,000 asteroids have been discovered so far, but of these only a few cross Earth’s orbit.

Raymond Bambery: Ninety-nine percent of them are outside of the orbit of Mars and offer no threat. And the 1,000 to 2,000 that come near Earth really don’t offer any major impact on Earth. We do have several hundred that have the potential of being hazardous.

Bambery said that scientists consider an asteroid to be potentially hazardous if it’s at least one kilometer in size, and it comes within 5 million miles of Earth. Only several hundred asteroids fall in this category, but one could, potentially, intersect the orbit of Earth at an inopportune time. Still, Bambery says, astronomers’ studies so far indicate that a devastating strike is unlikely in the near future.

Raymond Bambery: Nothing right now that we know of is due to impact the Earth in the next several thousand years, at least.

An Earth-crosser to watch is 99942 Apophis which is our closest-approaching Near Earth Asteroid right now. Bambery said that although Apophis is classified as potentially hazardous – and is about 300 meters in size – it doesn’t appear to be any threat on its passage in 2029. ‘It will be a great photo opportunity for astronomers,’ he said.

Our thanks today to Research Corporation
, a foundation for the advancement of Science.

Our thanks to:
Raymond Bambery
Near Earth Asteroid Tracking
Jet Propulsion Laboratory

D.C. Agle
Jet Propulsion Laboratory