  We investigate the light-cone effect on the Shapiro time delay. The extra
time delay caused by Jupiter on the 8th of September 2002 can be measured by
advanced VLBI (very long baseline interferometry). Our expression for the delay
is in complete agreement with that of Kopeikin (2001), in which he argued that
the excess time delay was due to the propagation of gravity. The present
letter, however, shows that the excess comes from nothing but the propagation
of light, namely the light-cone effect. To make a robust confirmation of
general relativity by the coming Jupiter event, it is important to take account
of the light-cone effect on the Shapiro time delay.
