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Videos of Near-Earth Asteroid
2005 YU55, November 8, 2011

YU552005 YU55's oblong appearance in the videos is primarily due to its movement across the sky: each individual image had an exposure time of two seconds, long enough that the asteroid moves slightly while the exposure was taken. All of the other white dots in the videos are background stars.

The asteroid's "wiggliness" is due to several factors including its actual shape, the manner in which light reflected off of different parts of it, and atmospheric conditions which can change from one exposure to the next.

6:59PM to 7:00PM PST (Video 1)

To find the asteroid, the telescope was pointed on the asteroid's known track but ahead of it, and was kept pointed at that single location until the asteroid came into the field of view (FOV) near the upper-right hand corner. This video reflects the actual speed of the asteroid as it passed.

7:26PM to 7:27PM PST (Video 2)

The asteroid moving from right to left.

7:56PM to 8:37PM PST (Video 3)
time-compressed, asteroid-centered

The asteroid appears to stay in the same place as the background stars go by behind it. Occasionally you can see the asteroid occult (cross directly in front of) a star.

9:06PM to 9:23PM PST (Video 4)
time-compressed, asteroid-centered

9:28PM to 9:33PM PST (Video 5)
time-compressed, asteroid-centered

The faint gray smudge occulted by the asteroid three seconds into the video is a distant galaxy.

9:42PM to 9:54PM PST (Video 6)
time-compressed, asteroid-centered

9:56PM to 10:30PM PST (Video 7)
time-compressed, asteroid-centered


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