  Trapping of bodies by waves is extended from electromagnetism to gravity. It
is shown that gravitational waves endowed with angular momentum may accumulate
near its axis all kinds of cosmic debris. The trapping mechanism in both cases
can be traced to the Coriolis force associated with the local rotation of the
space metric. The same mechanism causes the Trojan asteroids to librate around
the Sun-Jupiter stable Lagrange points $L_4$ and $L_5$. Trapping of bodies in
the vicinity of the wave center could also be related to the formation of
galactic jets.
