杏吧原创

DARK energy, the mysterious stuff thought to be causing the expansion of the universe to accelerate, has been found in our own galactic backyard.

In 1998, astronomers found that distant supernovae were fainter than expected, which suggested that the universe was expanding faster than expected. They attributed it to something called dark energy, the nature of which remains a mystery.

鈥淭he case for [dark energy] would be much stronger if it could be detected in our neighbourhood, where the interpretation of [data] is easier than in the distant universe,鈥� says of the University of Alabama, Tuscaloosa.

So a of the University of Turku in Finland, which included Byrd, studied the motion of the local group of galaxies in the region around the Milky Way and Andromeda galaxies.

The team say that the motion of small galaxies can only be explained by a model that includes dark energy. What鈥檚 more, the inferred density of dark energy here tallies well with its density in the distant universe ().

Cosmologist of the University of California, Davis, cautions that the motion of the local-group galaxies is governed by the distribution of dark matter, not dark energy, which becomes important only at much larger scales.