Number 225 (Story #2), May 8, 1995 by Phillip F. Schewe and Ben Stein JET-PROPELLED PULSARS . Observations made with the Rosat x-ray satellite reveal the presence of a gas jet shooting out of the Vela pulsar, some 1500 light years from Earth. University of Wisconsin astronomers Craig Markwardt and Hakki Ogelman believe the jet (20 light years long) may indicate a new mechanism for pulsar propulsion. Some pulsars have been observed to move at high speeds (hundreds of km/sec) through the sky. Theorists have thought this motion was essentially the pulsar's reactive rebound away from the asymmetrical supernova that gave birth to the pulsar in the first place. But now rocket power may be another way to move pulsars. The jet may also be a way of accounting for some of the energy lost by a pulsar over time, a loss resulting in a slowing of the pulsar's rotation. Moreover, the idea that some pulsars are blasting themselves out of the plane of our galaxy might contribute to the debate over whether the source of mysterious gamma bursts seen all over the sky are very distant objects or relatively nearby pulsars that have been ejected from our galaxy. (Nature, 4 May 1995.)