spacetoday.net: Galaxy data used to study dark energy

Posted: Sat, Feb 2, 2008, 3:59 PM ET (2059 GMT)
Dark energy map (ESO)

Astronomers are using observations of thousands of galaxies to determine if dark energy, a mysterious force thought to be responsive for the acceleration of the expansion of the universe, actually exists. In a paper published in the latest issue of the journal Nature, European scientists described how they are using spectroscopic data of thousands of galaxies collected by the European Southern Observatory's Very Large Telescope. The observations allow astronomers to measure the local motions of galaxies, which create distortions in the cosmic redshift data that astronomers can then use to probe for the existence of dark energy. Initial examinations of the data do support the existence of dark energy, but astronomers said they cannot yet rule out a competing explanation, an alternative theory of gravitation.