Nasa disappointed as LCROSS fails to produce the large plume of debris needed to prove water exists on lunar surfaceNasa moon LCROSS strike - as it happenedNasa's hopes of filming a spectacular crash on the moon were dashed today when satellite and telescope imagery failed to record the enormous plume of rock and dust that scientists had predicted.The US space agency steered two parts of a spacecraft, called LCROSS, into the moon at more than 9,000 kilometres per hour, in the final act of a mission designed to look for signs of water.Nasa scientists anticipated the impact would knock enough dust and rock out of the lunar surface to form a 10km-high cloud of debris that could be scanned for evidence of frozen water.But when the collision occurred at 12.31pm today, no signs of the plume were spotted, even from the nearby second stage, which crashed into the moon four minutes later.The disappointment came a day after staff at Nasa's headquarters in Washington DC faced a flood of calls from people who objected to the agency "bombing" the moon, some of whom feared the damage would disrupt tides on Earth and even their menstrual cycles.At a Nasa press conference, Anthony Colaprete, principal investigator on the LCROSS mission, said of the missing plume: "We haven't been able to see it clearly in our data yet." He added that scientists were working "feverishly" on information sent back from LCROSS.The spacecraft ploughed into an existing 100km-wide moon crater called Cabeus which is permanently in shade at the lunar south pole. Scientists believe the crater may contain frozen water that would be kicked up by the impact.One theory is that the impact site was unexpectedly hard and that rock and soil gouged out by the impact failed to rise high enough to be lit up by sunlight."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 Vincent Eke, an astronomer at the University of Durham who helped Nasa choose the impact site. "It might mean we don't get sufficient data, which would be a shame," he added.