Scientists were celebrating tonight after confirmation that a European spacecraft had landed safely on Saturn’s icy cloud-covered moon Titan after a seven year journey.
The Huygens probe parachuted through Titan’s thick, smoggy atmosphere to reach the surface at about 11.30am.
It continued transmitting signals for hours afterwards, indicating that it had weathered the descent and survived the landing.
Scientists believe the nine foot wide craft has come to rest on a stable, relatively hard surface. There was speculation that it might have sunk into tarry sludge or splashed into a lake or sea of liquid lighter fuel, in which case the probe was not expected to last long.
Experts are now anxiously waiting for the first images taken by Huygens’ panoramic camera.
They are expected to reveal a truly alien world. Titan, bigger than the planet Mercury, is the only moon in the Solar System with its own atmosphere, made of a smoggy blanket of nitrogen, methane and ammonia.
The surface is thought to consist of frozen methane and ethane, but may have steep mountains, craters, volcanoes and even lakes and seas.
In many ways Titan resembles the earth before the birth of life four billion years ago.
Scientists believe it will act as the perfect laboratory for studying the early earth.
Finding earth-type life on Titan is extremely unlikely with temperatures of minus 180C. However, one group of scientists claims conditions on the moon could support specially adapted life forms.
Huygens was carried to Saturn by Nasa’s Cassini spacecraft on an epic two billion mile journey.
It separated from its mothership on Christmas Day and navigated itself to Titan using autonomous guidance systems developed in Britain.
The first indication that Huygens had landed came from a carrier signal transmitted from the probe and picked up by radio telescopes on earth.
The signal, used to transmit data to Cassini, was too weak to yield any information, but it proved that Huygens was on the ground.
Hours later, mission controllers at the European Space Agency’s operations centre at Darmstadt, Germany, confirmed that they were receiving a stream of data relayed from Huygens by Cassini.
The news was passed via a live link to scientists and journalists gathered at the Royal Society in London.
Among them was Professor Colin Pillinger, chief planetary scientist at the Open University, who led Britain’s ill-fated Beagle II mission to Mars.
The success of Huygens is in sharp contrast to the loss of Beagle II, which vanished while attempting to land on Mars on Christmas Day 2003.
Prof Pillinger said: “It would have been the end of the world if we hadn’t got this one down. There’s now no doubt that Esa’s confidence will be restored in landings. It had a nasty upset with Beagle.”
He hoped Huygens would inspire Esa to give the green light for a new Beagle mission to Mars in 2009.
British scientists and engineers played key roles in the Huygens mission.
The probe’s critical flight software and parachute systems were designed by British companies, and UK scientists supplied some of the craft’s most vital instruments.
The first instrument to touch Titan’s soil, the Surface Science Package (SSP) was all British.
It contains eight sensors to investigate the physical properties of Titan’s surface and was built by teams from the Open University in Milton Keynes, the Rutherford Appleton Laboratory in Didcot, Oxfordshire and the University of Southampton.