ASTEROID TO buzz Earth on Monday. “Asteroid 2011 MD, a chunk of rock estimated to be 25 to 55 feet (8 to 18 m) across, is expected to pass less than 8,000 miles above Earth’s surface around 1 p.m. EDT (17:00 UT) on Monday, June 27th.” That’s close, and it was only discovered a few days ago. It’s fairly little as asteroids go, of course.