An asteroid the size of a jumbo jet will have a close encounter with Earth today (Sept. 1), zooming past our planet at about one-third the average distance to the moon. Asteroid 2011 ES4 will make its closest approach today at 12:12 p.m. EDT (1612 GMT), according to NASA . At that time, it will be about 75,400 miles (121,000 kilometers) from Earth. Because the object's orbit isn't well known, it could pass even closer than that, at a distance of just 45,400 miles (73,000 km), NASA added. "Will asteroid 2011 ES4 hit Earth? No!," NASA's Asteroid Watch outreach arm wrote on Twitter . "2011 ES4's close approach is 'close' on an astronomical scale but poses no danger of actually hitting Earth." The asteroid measures somewhere between 72 feet to 161 feet in diameter (22 to 49 meters), or about the size of a commercial airliner. During its close approach, it will be traveling at a speed of 18,253 mph (29,376 kph). Video: Airplane-size as...