impulse engines

Wired! Magazine’s science desk has an interesting profile on the research of two astrophysicists from Harvard aimed to identify theoretical hypervelocity stars.

Our Sun and Solar System churns through the Milky Way at seven hundred thousand kilometres per hour, but this is a relative snail’s pace compared to rogue stars that have been clocked with speeds millions of kilometres per hour hurling away from galaxies. Scientists believe that such ejections happen when a pair of stars waltzes too close to a black hole and one gets flung away. The astrophysicists believe that there’s no reason to believe that stars could not be travelling much faster even, and that there could be a trillion stars in the universe shuttling from galaxy to galaxy at just under the speed of light. Of course, there might also be a planetary system in tow on this grand tour—implying mechanical space-travel might not be the only means of reaching other worlds. Capturing a lone star streaking across the void of the intergalactic medium is outside the competency of today’s telescopes, however.