At the time of its closest approach to Earth at approximately 2:25 p.m. EST (11:25 a.m. PST/ 19:25 UTC), the asteroid will be about 17,150 miles (27,600 kilometers) above Earth's surface.
The commentary will be available via NASA TV and streamed live online at:
In addition to the commentary, near real-time imagery of the asteroid's flyby before and after closest approach, made available to NASA by astronomers in Australia and Europe, weather permitting, will be streamed beginning at about noon EST (9 a.m. PST) and continuing through the afternoon at the following website:
A Ustream feed of the flyby from a telescope at NASA's Marshall Space Flight Center in Huntsville, Ala., will be streamed for three hours starting at 9 p.m. EST (8 p.m. CST). To view the feed and ask researchers questions about the flyby via Twitter, visit: