Three scientists have won the 2011 Nobel Prize in Physics for the discovery of the accelerating expansion of the Universe through observations of distant supernovae.
Half of the 10 million Swedish crowns went to American Saul Perlmutter and the other half to a second research team, US-born Brian Schmidt, who is based in Australia, and US scientist Adam Riess.
“They have carefully studied several dozen exploding stars, called supernovae, in faraway galaxies and have concluded that the expansion of the Universe is speeding up,” prize awarder, the Nobel Committee for Physics at the Royal Swedish Academy of Sciences, said.
"The discovery came as a complete surprise, even to the laureates themselves,” the committee added in a statement.
The Nobel committee said for almost a century, the Universe has been known to be expanding as a consequence of the Big Bang about 14 billion years ago. But the discovery that the expansion is accelerating is “astounding”. “If the expansion will continue to speed up, the universe will end in ice,” the Nobel committee said.
The acceleration is thought to be driven by dark energy, although cosmologists have little idea what that is. They estimate that dark energy - a kind of inverse gravity, repelling matter that comes close to it - accounts for around three quarters of the universe.
Read more information on the Nobel Prize winners.