First images shot of planet beyond our solar system

Astronomers have captured the first picture of a planet orbiting a star beyond our own solar system with a technique that could soon open the way to seeing other worlds with extraterrestrial life.

The scientists say that the planet is five times the size of Jupiter - itself the biggest known planet - but is far too cold to offer much hope of harbouring life as we know it.

However, the sophisticated imaging technology used by the European Southern Observatory's mountain-top telescope in Chile could be refined further to see Earth-sized planets where life may have evolved, said Gael Chauvin, the leader of the research team.

Last September, the European Southern Observatory first reported the presence of a mysterious red object close to a brown dwarf star.

The object was about 100 times fainter than the star, which was itself an extremely faint speck of light in the southern constellation of Hydra about 200 light years away.

Using sophisticated optical techniques to eliminate interference from the Earth's atmosphere, the astronomers managed to capture direct images of the planet and its companion star earlier this year.

"Our new images show convincingly that this really is a planet, the first planet that has ever been imaged outside of our solar system," Dr Chauvin said.

"The companion is what we can call a giant planet of about five Jupiter masses. We are now sure that this object is a red companion bound to the primary [star].

"We cannot expect life on it, but it is the first detection of a planetary mass companion and we can hope in the future, perhaps 10 years or 20 years, we might be able to detect planets around other stars like Earth," Dr Chauvin said.

Benjamin Zuckerman, professor of physics and astronomy at the University of California at Los Angeles, and a member of the team, said that he was 99 per cent confident that the image showed a true planet orbiting its sun.

"The two objects, the giant planet and the young brown dwarf, are moving together. We have observed them for a year, and the new images essentially confirm our 2004 finding," Professor Zuckerman said.

The planet has a wide orbit around its star, about 55 times the distance between the Earth and the Sun, and would not warm up enough for water to exist in a liquid state - thought to be essential for the evolution of life.

Astronomers have named the planet 2M1207b and measurements of its electromagnetic spectrum suggest that water molecules may exist in the form of ice particles, which confirms that the planet must be too cold for water to have evaporated away into space.

Dr Chauvin said that the planet probably did not form like the other planets of the solar system.

"Instead it must have formed the same way our Sun formed, by a one-step gravitational collapse of a cloud of gas and dust," he said.

Anne-Marie Lagrange, an astronomer at the Grenoble Observatory in France, said the discovery was an important milestone and has implications for the future exploration of distant "exoplanets" beyond the solar system.

"Our discovery represents a first step towards one of the most important goals of modern astrophysics - to characterise the physical structure and chemical composition of giant and, eventually, terrestrial-like planets," Dr Lagrange said.

- INDEPENDENT