Auroras might identify distant planets

British planetary scientists say evidence suggests auroras like Earth's occur on bodies outside our solar system and could help in the search for alien worlds. Auroras occur on several planets within our solar system, they said, and the brightest -- on Jupiter -- are 100 times brighter than those on Earth and similar auroras could be responsible for radio emissions detected from a number of objects outside our solar system. Those emissions are strong enough to be detected at huge distances, meaning auroras could provide an effective way of observing new objects outside our solar system, University of Leicester researcher Jonathan Nichols said. Auroras occur when charged particles in solar wind enter an object's magnetosphere and collide with atoms in its upper atmosphere, causing them to glow and also emitting radio waves into space. "We have recently shown that beefed-up versions of the auroral processes on Jupiter are able to account for the radio emissions observed from certain 'ultracool dwarfs' -- bodies which comprise the very lowest mass stars -- and 'brown dwarfs,' failed stars which lie in between planets and stars in terms of mass," Nichols said. "These results strongly suggest that auroras do occur on bodies outside our solar system, and the auroral radio emissions are powerful enough -- one hundred thousand times brighter than Jupiter's -- to be detectable across interstellar distances," he said in a university release Monday. This could lead to the discovery of planets and objects outside our solar system that might not be identifiable by other methods, the researchers said.