NASA scientists will be tracking space rock with antennas of the agency’s Deep Space Network at Goldstone, Calif., as it safely flies past Earth slightly closer than the moon’s orbit on November 8. This space rock is asteroid 2005 YU55, a veritable mini-world roughly 1,300 feet (400 meters) wide nearly four football fields across that will zoom by Earth inside the orbit of the moon.Tracking of the aircraft carrier-sized asteroid will begin at 9:30 a.m. local time (PDT) on November 4, using the massive 70 meter (230-foot) Deep Space Network antenna, and last for about two hours. The asteroid will continue to be tracked by Goldstone for at least four hours each day from November 6 through November 10. Radar observations from the Arecibo Planetary Radar Facility in Puerto Rico will begin on November 8, the same day the asteroid will make its closest approach to Earth at 3:28 p.m. PST.
The trajectory of asteroid 2005 YU55 is well understood. At the point of closest approach, it will be no closer than 201,700 miles (324,600 kilometers) or 0.85 the distance from the moon to Earth. The gravitational influence of the asteroid will have no detectable effect on anything here on Earth, including our planet’s tides or tectonic plates. Although 2005 YU55 is in an orbit that regularly brings it to the vicinity of Earth (and Venus and Mars), the 2011 encounter with Earth is the closest this space rock has come for at least the last 200 years. The last time a space rock as big came as close to Earth was in 1976, although astronomers did not know about the flyby at the time. The next known approach of an asteroid this large will be in 2028.