BOSS mapped the locations of 1.2 million galaxies to make the measurements. The new distance measurements were presented at the meeting of the American Astronomical Society by Harvard University astronomer Daniel Eisenstein, the director of the Sloan Digital Sky Survey (SDSS-III).
In the image, the gray spheres show the pattern of the Baryon Acoustic Oscillations (BAO) from the early Universe. Galaxies today have a slight tendency to align on the spheres -- the alignment is greatly exaggerated in this illustration. By comparing the size of the spheres (white line) to the predicted value, astronomers can determine to one-percent accuracy how far away the galaxies are. This concept allowed the scientists to arrive at their measurement of the size of the Universe.
The Baryon Oscillation Spectroscopic Survey is an astronomical survey that measures the rate of expansion of the universe using the spatial distribution of Luminous Red Galaxies (LRG) and quasars. It is one of four components of the Sloan Digital Sky Survey.
SDSS-III is used to cover distant quasars at far reaches of the universe, the distribution of galaxies, the properties of stars in the Milky Way and also subjects such as dark matter and dark energy in the universe. Its instruments can make detailed measurements of 1000 galaxies at a time.
In 2012, BOSS had released their most accurate measurement yet of the distance scale of the universe during the era when dark energy activated.
