The images above show the asteroid's movement among the background stars. The three pictures are of the same region in space, taken a half hour apart. The asteroid 1998 KY26 is the little dot that moves among the background stars from upper-left to lower-right in the frames.
The asteroid 1998 KY26 was discovered by Tom Gehrels on the night of May 28, 1998 (UT) during a routine scanning session. Although appearing as a small dot on the screen like any other asteroid, this near-Earth asteroid has some interesting properties. First, it passed close enough to the Earth for radar observations to be taken. From light curve measurements, its rotation period was calculated to be 10.7 minutes - the fastest rotating asteroid known. In fact, it is the fastest known rotating body in the solar system! Also, because of its orbit, this asteroid is the most accessible to spacecraft among those asteroids with well known orbits. As of 2002 July 28, 1998 KY26 was still the most accessible (lowest DeltaV = 3.9 km/s) asteroid among those NEOs with well-determined orbits.
Reference: 1998 KY26 Science Paper
Ostro, S.J., P. Pravec, L.A.M. Benner, R.S. Hudson, L. Sarounova, M.D. Hicks, D.L. Rabinowitz, J.V. Scotti, D.J. Tholen, M. Wolf, R.F. Jurgens, M.L. Thomas, J.D. Giorgini, P.W. Chodas, D.K. Yeomans, R. Rose, R. Frye, K.D. Rosema, R. Winkler, & M.A. Slade. 1999. Radar and optical observations of asteroid 1998 KY26. Science 285, 557-559.