This year's Nobel Prize in Physics 2011 has been awarded to Saul Perlmutter, Brian P Schmidt and Adam G Riess for revealing the final fate of the universe.
After studying several dozen supernovae, the three discovered that the universe is expanding at an ever-accelerating rate. Working separately - Perlumtter in one team, and Schmidt and Reiss in another - they presented their findings in 1998. Both teams said they'd expected to find the opposite.
After examining a particular type of supernova, known as type Ia, the two teams found over 50 distant supernovae whose light was weaker than expected - a sign that the expansion of the universe was accelerating. If the acceleration continues, the universe will end in ice.
The acceleration is thought to be driven by dark energy - but the dark energy itself remains unexplained. All that's known is that it makes up about three quarters of the universe.
Half the $1.5 million award will go to Saul Perlmutter, with the other two scientists sharing the remainder.
Perlmutter heads the Supernova Cosmology Project at the University of California, Berkeley. Schmidt leads the High-z Supernova Search Team at the Australian National University in Weston Creek, Australia, while Riess is an astronomy professor at Johns Hopkins University and Space Telescope Science Institute in Baltimore, Maryland.