Giant asteroid buzzes past Earth; scientists discover a moon

World Today

Asteroid That Flew Past Earth Has Moon

An asteroid measuring about a third of a mile (half a kilometer) in diameter made a relatively close, but harmless pass by Earth on Monday (January 26), NASA said.

The asteroid passed about 745,000 miles (1.2 million kilometers) from Earth, roughly three times farther away than the moon. During the flyby, scientists even discovered that the asteroid had a moon of its own.

A small telescope or binoculars was needed to see the asteroid, which is known as 2004 BL86.

The asteroid, which orbits the sun every 1.84 years, was discovered 11 years ago by the Lincoln Near-Earth Asteroid Research, or LINEAR, telescope in New Mexico.

Scientists plan to map the asteroid’s surface with radar during the flyby in hopes of learning more about its size, shape, rate of rotation and other features.

Asteroid 2004 BL86 will be the largest asteroid to pass this close to Earth until asteroid 1999 AN10 flies by in 2027, NASA said.

NASA currently tracks more than 11,000 asteroids in orbits that pass relatively close to Earth. The U.S. space agency says it has found more than 95 percent of the largest asteroids, those with diameters 0.65 miles or larger, with orbits that take them relatively close to Earth.

An object of that size hit the planet about 65 million years ago in what is now Mexico’s Yucatan peninsula, triggering a global climate change that is believed to be responsible for the demise of the dinosaurs and many other forms of life on Earth.

Two years ago, a relatively a small asteroid exploded in the atmosphere over Chelyabinsk, Russia, leaving more than 1,500 people injured by flying glass and debris. That same day, an unrelated asteroid passed just 17,200 miles from Earth, closer than the networks of communication satellites that ring the planet.

Story compiled with information from Reuters.