First picture of a planet outside 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 into other worlds with extraterrestrial life.

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 into other worlds with extraterrestrial life.

The scientists say the planet is five times the size of Jupiter - previously the biggest known planet - but is far too cold to offer much hope of harbouring life.

However, the sophisticated imaging technology used by the European Southern Observatory's mountain-top telescope in Chile could be refined 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 red object close to a brown dwarf star. The object was about 100 times fainter that the star, which was itself an extremely faint speck of light in the southern constellation of Hydra about 200 light years away.

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

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

"The companion is what we can call a giant planet of about five Jupiter masses. We are now sure 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 similar to 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 he is 99 per cent confident the image shows 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 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 liquid state - one of the prerequisites thought to be essential for life.

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

Dr Chauvin said 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.

The research findings and images of the planet are scheduled to be published in the journal Astronomy and Astrophysics.