Mapping Dark Matter
Led by British scientist Richard Massey, a team at the California Institute of Technology, Pasadena, has mapped one of the ‘known unknowns’ – dark matter. The news has just been released by the journal Nature:
Hot on the heels of evidence last year that dark matter really does exist (see 'Dark matter spied in galactic collision'), the same technique has been used to map this uncharacterized mass across half a million distant galaxies.
Massey used a technique called gravitational lensing, whereby the pull from dark matter caught in between a star and the observing telescope alters the path of the light, and allows the presence of dark matter to be inferred.
Massey notes that a few odd discrepancies remain in the dark matter map. These could be the result of errors in observations. "If they are real," Massey says, "they will bring a huge shock."