It missed



2011 MD appears as the track near the center of the picture

Close call - but we're not dead. Yet 

Asteroid 2011 MD buzzed by the Earth yesterday

It turns out it was about the size of a school bus and travelled at a speed of about 63,000 miles per hour.

It was only visible in the southern hemisphere with a good telescope. If it had passed within our field of view, with our clear night and dark skies, we could have seen it at Frosty Drew.

If it had hit the Earth, the chances are a good chunk of it would have reached the surface and caused a "decent-sized crater," said Ben Weiss, an MIT planetary scientist. "You wouldn't want something like this to land on Manhattan."

Based on its orbit, it's likely 2011 MD will be back in the future. Earth gets struck by asteroids this size every 50 years, on average.

, coming as close as 7500 miles. When it was first spotted only last week, its exact size was unknown.