A large asteroid, known as 2004 XP14, raced past the Earth early Monday. Scientists say it posed no threat to the planet, but serves as a reminder of the hazards encountered in space.
The rocky space body, thought to be 800 meters wide, came within 430,000 kilometers of Earth, almost as close as the moon.
Discovered in December, 2004, the asteroid is big enough to cause some serious damage if it hit us. That did not happen, but many such collisions with near-Earth objects have occurred in the past. Sixty-five million years ago, a much larger asteroid struck the Yucatan region of Mexico and the resulting atmospheric disruptions are believed to have caused the extinction of dinosaurs.
Hollywood has seized on the scenario of killer objects in space in several action-movies. Two of the best known were released in 1998, and both dealt with the theme in typical Hollywood fashion, with a heavy dose of drama and destruction, but very little science.
In the film Armageddon, Bruce Willis was sent to destroy an asteroid the size of Texas, described here by Billy Bob Thornton.
"It's what we call a global killer. Nothing would survive, not even bacteria," said Thornton in the film. "
The United States government just asked us to save the world," said Willis. "Anybody want to say no?"
In the film Deep Impact, the danger comes from a pair of killer comets, composed of ice, rock and dust, described by Morgan Freeman.
"Last summer, two comets were discovered that are on a collision course with Earth," he said.
The U.S. space agency NASA tracks thousands of near-Earth objects that could pose a hazard if they struck the planet. The agency has classified more than 700 asteroids as potentially hazardous, but says those rocky space bodies are rich in minerals and are also a possible resource to be exploited.
Asteroid 2004 XP14 passed harmlessly by the Earth in the early hours Monday, universal time. It was seen easily with amateur telescopes, with the best views available in North America.
Scientists say this asteroid will have 10 more close encounters with Earth over the next century, but none is expected to pose a threat to the planet.