First things first: Earth is in no danger from mass extinction, or any Holly-wood style destruction. That said, the 90 foot wide Asteroid 2011 MD will pass within 7,430 miles of our home planet. For reference, that distance is about half the diameter of the Earth, and will be the fifth-closest observed approach an asteroid has made to the Earth.
In terms of speed and orbit, 2011 MD is actually quite similar to Earth. Because of this, the space rock intercepts our planet’s orbit every 13 years or so. The close fly-by and similar speeds mean that it would be an ideal candidate for ground-based viewing, but that won’t be so likely this time around. Unfortunately, the asteroid will pass on the sunlit side of the Earth, and likely be best observed with radio telescopes.
Though tomorrow’s close encounter will lack some drama, future encounters with 2011 MD could be far more interesting. The swing by with Earth is going to put a crimp in the asteroid’s orbit, perhaps bringing it even closer next time around. Which wouldn’t be so bad considering that the diminutive asteroid would fizzle up in the atmosphere, making for quite a spectacular show.
(via Bad Astronomy)