Note the difference in the length of the star trails.  This object is just less than
twice as far from earth on the 16th as on the 17th.

Both sets of images are 20, 30sec frames stacked, tracking on the asteroid,
(a period of about 12 minutes)

The link below presents the same data shown in the two images above,
presented as a movie.  Note, the two movies are about 0.5 megs each.
2002 NY40 Movies