Scientists to spot alien oceans with next generation of telescopes

A US space telescope set for launch in 2014 could reveal the presence of oceans on planets outside the Solar System, say scientists.

Detecting water on Earth-like planets would offer the tantalizing prospect they could sustain life, and scientists hope the reflection of light, or "glint", from mirror-like ocean surfaces could be picked up by the upcoming generation of space telescopes.

Tyler Robinson at the University of Washington in Seattle said he thinks the new technique could be used in the search for the "holy grail" for exoplanet astronomy, a possible sister planet to Earth.

"We're focussing on a class of extra-solar planets yet to be detected, so things comparable in size and composition to the Earth and similar distances from their central star as the Earth is from the Sun," the BBC quoted him as saying.

"The goal is to find something Earth-like in almost every sense of the world so we can even prove it has liquid oceans on its surface," he added.

This kind of ocean could be the signature of a planet where life had developed in the same way as it did on our own planet.

Tyler Robinson hopes "glint" - the effect seen when light is reflected from an ocean's surface - may reveal the presence of Earth-like planets beyond our cosmic neighbourhood.

The research has been published in Astrophysical Journal Letters.