This first infrared image of asteroid 2005 YU55 was captured by the Keck II telescope.
This radar image of asteroid 2005 YU55 was obtained on Nov. 7, 2011, at 11:45 a.m. PST (2:45 p.m. EST/1945 UTC), when the space rock was at 3.6 lunar distances, which is about 860,000 miles, or 1.38 million kilometers, from Earth.
This radar image of asteroid 2005 YU55 was obtained on Nov. 6, 2011, at 1:45 p.m. PST (4:45 p.m. EST/2145 UTC), when the space rock was at 6.4 lunar distances, which is about 1.5 million miles, or 2.46 million kilometers, from Earth.
This sky chart shows the motion of asteroid 2005 YU55 as it zooms by Earth on the evening of Nov. 8, 2011.
Despite making an unusually close pass by the Earth, asteroid 2005 YU55 poses no threat of impact with our planet.
In April 2010, this radar image of the near-Earth asteroid 2005 YU55 was taken by the Arecibo radio telescope in Puerto Rico. On Nov. 8, 2011, this large space rock zips by Earth again and will be surveyed by radar, visual and infrared equipment.
This still from a NASA animation by Jon Giorgini of the Jet Propulsion Laboratory shows the trajectory of asteroid 2005 YU55 as it passes between Earth and the moon on Nov. 8, 2011.
Astronomer Robert McMillan, discoverer of asteroid 2005 YU55, sits in the SPACEWATCH control room on Kitt Peak.
NASA's 70-meter Goldstone antenna located near Barstow, Calif. The antenna can be used as a radar tool to study near-Earth asteroids during close flybys.
Astronomer Robert McMillan, discoverer of asteroid 2005 YU55, observing with an experimental instrument unrelated to his asteroid work in 2007, in the dome of the Steward Observatory's 2.3-meter Bok Telescope on Kitt Peak.
Astronomers use the huge Arecibo Observatory, a radio telescope in Puerto Rico, to study the close flyby of Earth by asteroids.
The Robert C. Byrd Green Bank Telescope in West Virginia, the largest steerable radio telescope in the world, is observing 86 planetary systems that may contain Earth-like planets in hopes of detecting signals from intelligent civilizations
Astronomer Brian Warner, director of the Palmer Divide Observatory, is leading a campaign of largely backyard astronomers to observe asteroid 2005 YU55 during its Nov. 8, 2011 close flyby of Earth.
Left: radar image of asteroid 2005 YU55 was generated from data taken in April 2010 by the Arecibo Radar Telescope in Puerto Rico. Right: diagram of the trajectory for asteroid 2005 YU55 — November 8-9, 2011