Scientists are claiming to have come up with the largest-ever 3D map of the universe, capturing the locations and distances of more than a million galaxies.
According to astronomers, who are collaborating with the Sloan Digital Sky Survey III (SDSS-III), the map covers a total volume equivalent to that of a cube 4bn light years on a side.
The scientists involved in SDSS-III have been working to map the Milky Way, search for extrasolar planets, and solve the mystery of dark energy in the universe. They have been using a 2.5-m wide-angle optical telescope at Apache Point Observatory in New Mexico.
Daniel Eisenstein from the Harvard-Smithsonian Center for Astrophysics is the director of SDSS-III.
"We want to map the largest volume of the universe yet, and to use that map to understand how the expansion of the universe is accelerating," said Eisenstein.
Apparently, this latest 3D map is the centerpiece of data that has been publicly released from the first two years of a six-year survey project.
The 3D map, claim the scientists, includes images of 200m galaxies and spectra of 1.35m galaxies. They said spectra take more time to collect than photographs, but provide the third dimension by letting astronomers measure galaxy distances.
Geometric view of the universe
Michael Blanton of New York University said the goal is to create a catalogue that can be used by future scientists to unlock more insights about the universe.
The ongoing SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) is currently working to measure the positions of massive galaxies that are up to 6bn light years away, as well as quasars. The latter are giant black holes that can be up to 12bn light years from Earth. Quasars gobble up stars and gas in the universe.
Via this new map and the SDSS-III project, the scientists are hoping to retrace the history of the universe over the past 6bn years. The aim is to help other astronomers glean better estimates for how much of the universe is made up of dark matter and dark energy.
"Dark matter and dark energy are two of the greatest mysteries of our time," said David Schlegel of Lawrence Berkeley National Laboratory, the principal investigator of BOSS. "We hope that our new map of the universe can help someone solve the mystery."