Tonight will be Earth's closest call with an asteroid until 2027.
The asteroid about a third of a mile wide known as 2004 BL86 will pass within 745,000 miles of Earth this evening.
The space rock should be big enough and close enough for amateurs to spot using a small telescope or a powerful pair of binoculars — but it won't pose any risk to Earth in the foreseeable future, NASA's Jet Propulsion Laboratory says.
The asteroid was discovered 11 years ago, but this month it's coming as close to Earth as it will get for at least the next 200 years.
2004 BL86's flyby will be the closest pass by any known space rock this large until 1999 AN10's close encounter in 2027, according to NASA.
