Los Angeles: An asteroid the size of a tour bus---dubbed 2011 MD---has zipped harmlessly past Earth.
The space rock flew 7,600 miles above the Earth`s surface. It sailed high above the southern Atlantic Ocean at closest approach.
The asteroid was discovered last week by telescopes in New Mexico. It is between 15 feet and 60 feet wide. Scientists say asteroids this size sail past Earth every six years.
Earlier this year, a smaller space rock came within 3,400 miles of Earth.