The asteroid (132524) 2002 JF56 was the fly-by target of the New Horizons mission on June 
13,2006. In order to allow a good planning of the fly-by, ground based observations of the 
asteroid were performed on May 2006 at ESO VLT. The analysis of the observations is used for 
cross-calibration and comparison with the data from the mission spacecraft.

A set of R filter broadband images and reflectance spectra were taken with FORS2 of the ESO
VLT for a total of three nights (May 25, 30 & 31, 2006). Each observational cycle spans a 
time interval of about one hour per night. The observations were performed about two weeks 
before the fly-by, when the asteroid was at a heliocentric distance of 2.5 AU.
Results. The reflectance spectra of 2002 JF56 resemble those of S-type asteroids. From the 
magnitude of the asteroid, an efective diameter of (2.17 ± 0.01) km is estimated and a lower 
limit for the axis-ratio of (1.19 ± 0.02) is determined.