I live in Illinois. Some nights I telecommute (via the internet) to an observatory at Kitts Peak near Tucson, AZ, operated by University of Arizona. I participate by reviewing telescope images in search of "fast moving objects". The target objects appear to "move fast" because they are close to the Earth. The project is called "SpaceWatch FMO."
Early (1 a.m. local time) Monday morning, December 20, 2004, one of the images that I reviewed contained the tell-tale elongated trace of a near-earth asteroid. The observer on site at Kitts Peak (astronomer Robert McMillan) concurred and sent the observation to the Minor Planets Center (MPC) at Harvard. He included sufficient detail on location, speed, direction, and brightness so that other observatories could find the object and help refine the measurements of its actual orbit. The effort was successful and on Tuesday, December 21, 2004, MPC assigned the designation "2004 YD5" to this asteroid and published the asteroid's orbital details..
Asteroid 2004 YD5 is the second closest approach by an asteroid on record. It passed "under" the south pole at an altitude of about 20,000 miles, closer than our geostationary satellites. It passed earth on its way toward apohelion near the orbit of Jupiter. Due to it's eccentric orbit, it was moving more rapidly than most asteroids as it passed earth. Its ordinary-appearing brightness in the initial image resulted from its small size (16 feet) and close approach to Earth. Because of its small size, rapid movement and the brightening moon, it quickly became very faint, and prospects for recovery by other observatories appeared to be diminishing.
SpaceWatch FMO Project has now discovered 18 confirmed near-earth asteroids during 2004. The project uses a 0.9 meter telescope and, in 2003, began using a "mosaic" (combination) of CCD's (image sensors) for recording the images.
Early in the morning of June 27, 2005, I discovered another asteroid. Since the first discovery, I had reviewed approximately 1400 images from SpaceWatch.
Here are some internet addresses with further documentation: