It was billed as one of the most ambitious missions in the history of space exploration. But Nasa's audacious attempt to smash two spacecraft into the surface of Moon in the search for water turned into a damp squib for millions of people today.The £49million 'bombing raid' was supposed to create a six-mile high cloud of dust that would be visible from telescopes on the Earth. But live pictures relayed back from the Moon showed no sign of an impact - even though both craft dived into a darkened crater as planned.
Nasa scientists were today analysing the data and images sent back to the Earth to find tell trace traces of ice in the debris. Millions of people had watched live on the internet as the Lunar Crater Observation and Sensing Satellite and its two-tonne Centaur rocket approached the Moon's south pole.
The rocket was first to crash, plunging into the pitch-black Cabeus crater at 12.31pm. Nasa hoped it would blast 350 tonnes of rock and dust into a cloud, leaving behind a dimple the third the size of a football pitch.
Travelling faster than a bullet, it was supposed to hit with the force of 1.5 tonnes of TNT and create a mini-crater about half the size of an Olympic pool. The second crash, caused by the smaller LCROSS probe, was to be about one-third as strong.
The first crash was filmed by the LCROSS probe, which had detached from the rocket the night before. It beamed live information to Earth from its five cameras and four scientific instruments as it flew above the impact zone before it too smashed into the surface four minutes later.
Scientists hoped to find evidence of ice at the bottom of dark craters at the Moon's poles, where temperatures are lower than minus 170C.
However, the big spectacle Nasa had promised failed to happen. The webcast images of the crater loomed larger and larger as the satellite approached on its collision course, but still showed no sign of debris.
Nasa officials said their instruments were working, but the planned live photos were missing. The only evidence of an impact was a small heat signature picked up by the LCROSS probe's infra-red camera. Expectations by the public for live plume video were probably too high and based on pre-crash animations, some of which were not by Nasa, said project manager Dan Andrews.
Nasa's director at the Ames Research Centre which monitored the mission Michael Bicay admitted: 'We didn't see a big splashy plume like we wanted to see.' Prior to impact some scientists had claimed that there was chance that it would be clear within an hour of the collision whether there was water on the Moon. Now Nasa say it will probably be two weeks before they have an answer.
Another issue regarding the impacts was the poor lighting, said Mr Andrews. Experts said the images could be essentially 'grey against black'. 'What matters for us is: What is the nature of the stuff that was kicked up going in?' he said. 'All nine instruments were working fine and we received good data.'
Mr Andrews said the science team was poring through the information - including what are supposed to be good images from ground-based telescopes on Earth - to answer the big question: Is there some form of water under the moon's surface that was dislodged?
It will probably be two weeks before scientists will be certain about the answer, he said.
Before the crash, mission scientists said there was a chance that if it was really moist under the crater, they'd know about water within an hour. That's not the case now, Mr Andrews said.
People who got up before dawn to look for the crash at Los Angeles' Griffith Observatory exchanged confused looks instead. Jim Mahon called the celestial show 'anticlimactic'. 'I was hoping we'd see a flash or a flare,' he said.
A British expert who helped the American space agency Nasa pick the location near the Moon's south pole said the lunar surface may not have reacted as expected.
But Dr Vincent Eke, from the University of Durham, stressed it was still too early to know if the mission had been a success or failure. 'If it turns out to be as dull as it looked, I'd imagine the soil just didn't respond as was hoped to being hit,' said Dr Eke. 'It might mean we don't get sufficient data, which would be a shame.'
Dr Eke's team discovered strong evidence of hydrogen - a key component of water - within cold permanently shadowed craters at the Moon's poles, where temperatures fall to minus 200C.
Finding water, which could be used for drinking, making fuel and providing oxygen, would have major implications for the future of moon exploration.
A ready supply of water would make it far more practicable to build lunar bases or launch missions to Mars from the Moon.
Dr Eke, who led a study of data from Nasa's 1998 Lunar Prospector mission which revealed hydrogen concentrated in darkened craters, said: 'There's absolutely no doubt that they hit the place they were aiming for, but how material gets thrown out from the surface depends on whether it's rocky or loose. If you hit a sponge, you're not going to see anything.
'It sounds like they got an infrared signal, but its too early to predict yet what they're likely to get.'
Last month new findings from three spacecraft, including India's Chandrayaan-1 probe, showed that small amounts of water might be chemically bound up with the Moon's soil.
Anthony Colaprete, principal investigator for the mission, cautioned: 'We don't anticipate anything about presence or absence of water immediately. It's going to take us some time.'
If hydrogen is present as water ice, then the data would imply the top metre of the surface in these craters holds about 200,000 million litres of water in total.
Preparation for impact comes as stunning thermal images of the far side of the Moon have been revealed for the first time.
The British-made Thermoteknix camera is onboard the LCROSS, and will be one of the instruments that will study the first plume of debris before crashing itself. 'The camera has worked flawlessly for nearly 100 days, and counting, in interplanetary space,' said Mr Colaprete.
'It provided the first thermal images of the far side of the moon and also images of Earth and the Moon from distances as great as 560,000km and 850,000 km away, respectively.'
The MIRICLE camera was developed by pioneering thermal imaging company Thermoteknix Systems, based in Cambridge. Dr Richard Salisbury, managing director of Thermoteknix, said: 'We are delighted to have been selected to play a critical part in Nasa's important mission to find water on the Moon, which is vital for the future of longterm space exploration.
