The Sloan Digital Sky Survey (SDSS) astronomers used 140,000 near-distant satellites to measure the expansion rate of the universe when it was only a quarter of its current age. To date, this is the best measure of the rate of expansion at any time in the 13.8 billion years since the Big Bang. Researchers from Irfu (CEA) and CNRS played a major role in this discovery.
Click here to read the press release in French on the CEA website