A Nasa space probe measuring the oldest light in the Universe has found that cosmic neutrinos made up 10% of matter shortly after the Big Bang.
Five years of study data also shows that the first stars took over half a billion years to light up the Universe.
WMAP launched in 2001 on a mission to measure remnants of light left over from the Big Bang.
More: http://news.bbc.co.uk/1/hi/sci/tech/7288463.stm