Asteroid 2001 YB5 was only discovered in December and it is now extremely close to the Earth. Although there is no danger of collision, astronomers say its proximity reminds us just how many objects there are in space that could strike our planet with devastating consequences. Astronomers and archaeologists suspect that our planet is struck by an object like 2001 YB5 about every 5,000 years, but this is a guess that?s not based on any definite evidence.

The asteroid passed less than twice the Moon?s distance from us – just 510,000 miles away – on Monday, January 7, which is extremely close in cosmic terms. YB5?s brightness suggests it?s a rocky body about 328 yards wide, which is large enough to wipe out an entire country if it struck the Earth.
read more

The odds are good that eventually our planet will be hit by an asteroid or a comet, as it has many times before. Engineers and scientists here at NASA?s Langley Research Center are trying to spot these hazards before they sit. One good place to set up an astronomical alarm system is on the Moon.

A large number of asteroids larger than a half-mile across are in orbits that bring them close to Earth. If any of them were to hit our planet, it would cause social and environmental upheaval. Locating the whereabouts of these objects is the major job of several Earth-based telescopic searches.
read more

Over the past millions of years, Earth has taken some major hits from asteroids. Where do these huge boulders come from and why are they in orbits near the Earth? Scientists now think the sun is to blame.

Asteroids most likely come from the dense area of gigantic, spinning rocks that exists between Mars and Jupiter. But scientists have a hard time explaining what might have dislodged so many of them from their stable asteroid belt and sent them hurtling towards Earth.
read more

About 35 million years ago, when dinosaurs were already extinct but the Appalachian Mountains were still covered in tropical rain forests, an asteroid more than a mile wide, moving at supersonic speed, crashed into the Atlantic Ocean off North America.

Traveling at about 70,000 miles per hour, the asteroid or comet dove through several hundred feet of water and several thousand feet of mud and sediment. Billions of tons of ocean water were propelled into the air as high as 30 miles and vaporized. Millions of tons of debris and rocks were ejected into the atmosphere. The collision incinerated everything along the East Coast, triggered gigantic tsunamis, and destroyed marine life in the surrounding area.
read more