Photo sequence showing the dust jet activating and then shutting down. ESA credit.
Comet 67P - Churyumov-Gerasimenko is acting like a spaceship that fires thrusters. The European Space Agency's Rosetta comet probe, currently orbiting the comet, caught a great view of a pocket of dust erupting from the surface of the comet. Since the comet itself is large, the relative movement effect of the short burst will not be very noticeable, but the spray will add to the comet's tail. Last week on the 13th, the comet reached its closest approach to the Sun (its perihelion) and will now be slowly heading towards the edge of the solar system.