NASA LCROSS Moon crash mission: debris plume spotted
By Tom Chivers
Published: 10:33AM BST 19 Oct 2009
NASA's first released image of the plume from the LCROSS impact Photo: NASA
Scientists had feared that the plume had been too small to be captured, as both observers on Earth and the Hubble Space Telescope failed to spot anything.
However, the spacecraft trailing behind the rocket, which itself hurtled into the Moon four minutes later, spotted a faint trace of ejecta rising around a kilometre (0.6 miles) into space.
Earth-bound observers would have been unable to spot any plume that was less than two kilometres high. LCROSS principal investigator Anthony Colaprete told New Scientst: "I think we are the only ones that have images.
"The ejecta had to only come out and get into the sunlight a little more than a kilometre [high] for us to see it. It only had to rise half as high."
It had been hoped that the plume would rise as high as 10km. But the hollow rocket and the slightly spongy surface of the Moon meant that this failed to materialise.
However, the lightweight impact, instead of a denser, cannonball-style design, meant that the crater would be wide and shallow rather than deep, kicking up more of the surface material the researchers are interested in.
Mr Colaprete said: "What we've been able to get with this is a nice, broad area at relatively shallow depth.
"That's kind of nice because we're interested in stuff a metre or 70 centimetres deep." Previous missions have detected hydrogen in the top 70cm of the lunar soil, which indicates that there may be water.
The researchers hope to have analysed the data from the LCROSS impact by mid-November. We will learn then whether there really is water on the Moon.
I'm damn sure I wouldn't be able to do what they did!
