Article @ Carnegie Institute:

'Interstellar space may be strewn with tiny whiskers of carbon, dimming the light of far-away objects. This discovery by scientists at the Carnegie Institution may have implications for the “dark energy” hypothesis, proposed a decade ago in part to explain the unexpected dimness of certain stellar explosions called Type1a supernovae.'

This is pretty cool stuff, if it pans out. Could have repercussions on estimated age of universe, distances between galaxies, rate of expansion, etc.

BTW, Carnegie has free public lectures for those near DC: . I've attended several with my youngest daughter and they are quite good.