  Taylor, Frail, Berger and Kulkarni have made precise VLBI measurements of the
size and position of the source of the radio afterglow of GRB 030329. They
report a size evolution compatible with standard fireball models, proper motion
limits inconsistent with the cannonball model, and a double source, i.e. "an
additional compact component" on day 51 after the GRB, totally unexpected in
the standard models. We outline a consistent interpretation of the ensemble of
the data in the realm of the cannonball model. The observed double source is a
radio image of the two cannonballs required in this model to explain the
gamma-ray and optical light curves of this GRB; their separation agrees with
the expectation. Thus interpreted, the observation of the two sources
--separated by a "hyperluminal" distance-- is a major discovery in
astrophysics: it pins down the origin of GRBs.
