Stars aren't shy about sending out birth announcements. They
fire off energetic jets of glowing gas traveling at supersonic
speeds in opposite directions through space. Although
astronomers for decades have looked at still pictures of stellar
jets, they now can watch movies of them, thanks to NASA's Hubble
Space Telescope. A diverse team of scientists led by astronomer
Patrick Hartigan of Rice University in Houston, Texas, has
collected enough high-resolution Hubble images over a 14-year
period to stitch together time-lapse movies of young jets
ejected from three stars. The moving pictures offer a unique
view of stellar phenomena that move and change over just a few
years. Most astronomical processes change over timescales that
are much longer than a human lifetime. The movies reveal the
motion of the speedy outflows as they tear through their
interstellar environments. Never-before-seen details in the
jets' structure include knots of gas brightening and dimming
over time and collisions between fast-moving an