PSI Senior Scientist Ed Tedesco took the images seen in this looped video of Near Earth Object 2005 YU55 as it passed close to Earth on Nov. 8. Tedesco used the 50-inch Robotically Controlled Telescope at Kitt Peak National Observatory in Arizona.
The video, made up of 14 exposures of 10 second each, was shot between 7:07 and 7:21 p.m. Tucson time when the asteroid was within 214,000 miles of Earth, or about 35,900 miles closer to the Earth than the Moon was at that time.
The telescope moved at the rate, and in the direction, that YU55 was moving and so the asteroid appears as a point and the stars as trails. Since the asteroid was moving at about 1.6 arcseconds per second, each star appears as a trail about 15 arcseconds long and parallel to the direction of the asteroid’s motion. An arcsecond is one-sixtieth of a minute of angular distance. During the 14 minutes covered by the video, 2005 YU55 moved across the sky by about two-thirds the apparent diameter of the full Moon.
