Tonight is the night that a mountain-sized space rock will barely miss the earth. Barely miss in a space sense that is.The asteroid 2004 BL86, as it is known to NASA, will become the largest space rock of its kind to zoom safely by the Earth until 2027. The space rock may be visible to onlookers with a pair of binoculars, or a small telescope, because of its significant size. At its closest approach, the asteroid will be some 745,000 miles from Earth. NASA says that is safely outside the orbit of the moon, and it poses no threat.

You can watch the passing of 2004 BL86 as it whizzes by the planet tonight live on NASA's website space.com. For those of you who like to try to catch it yourself, the asteroid is expected to reach a magnitude of +9, which is a little dimmer than the planet Neptune, and much brighter in the sky than Pluto.

Observers in the Americas, Europe, and Africa will have the best view at the asteroid's peak brightness, which will happen tonight between 7 p.m. and midnight central time.

Happy star gazing!