Voyager images reveal that three prominent clumps in Saturn's F ring w
ere short-lived, appearing rapidly and then spreading and decaying in
brightness over periods of similar to 2 weeks. These features arise fr
om hypervelocity impacts by similar to 10-centimeter meteoroids into F
ring bodies. Future ring observations of these impact events could co
nstrain the centimeter-sized component of the meteoroid population, wh
ich is otherwise unmeasurable but plays an import ant role in the evol
ution of rings and surfaces in the outer solar system. The F ring's nu
merous other trumps are much longer lived and appear to be unrelated t
o impacts.