Moon crash - 'Deep Impact' this wasn't
Updated on 09 October 2009
The fact that today's crash-landing on the moon of two Nasa spacecraft failed to produce the desired pyrotechnics does not mean it was a scientific failure, writes Tom Clarke.
There was no giant plume of debris, no mighty crash, no crystals of ice thrown kilometres high. "Deep Impact" this wasn't.
In fact, at the time of writing, no telescope on earth, or in space – Hubble was all eyes too – saw any plume at all. Claims Nasa had made that the impact might be visible with a 10-inch telescope from earth have almost certainly disappointed more than a few amateur astronomers who stayed up all night to see it.
While it may have been a PR flop, it doesn't look like it's been a scientific failure. The impact did happen and was spotted by sensors on board the probe following the rocket stage that hit the Moon.
It fell to the exhausted LCROSS science team who had been up for 36 hours to field questions about why their probe hadn't lived up to the hype. If they were disappointed, they weren't letting on -
"Exploration has surprises in it, and we certainly built our mission plan and our science plan around all aspects of the impact.
“We need to go and carefully look at the images and see what's in them," said Anthony Colaprete, principal investigator for LCROSS at NASA Ames Research Centre.
But the fact the scientists are having to scrutinise their data for evidence of anything at all makes the build-up and live TV coverage of the event embarrassing for Nasa. The animations sent out to media organisations in advance of the mission showed Hollywood-style pyrotechnics from the surface of the Moon.
As the 12-metre-long spent rocket smacked into the surface of the Moon, it was expected to kick up 350 metric tonnes of debris 10km into the atmosphere of the moon.
This plume of debris was going to be clearly visible to telescopes from earth – but more closely examined by the LCROSS shepherding space probe following the impactor to its fate – and reveal the presence (or absence) of water ice on the lunar surface.
What the live images beamed back from the probe showed were, if you looked very closely indeed, a tiny bright spot on the surface where they think the impact might have happened. That's plenty for the scientists - the spectrometers on board the LCROSS probe saw the impact and will see any ice and rock from the material that was inevitably kicked up.
But it wasn't much for Nasa’s administrator, Major General Charles Bolden, who was lined up for a live interview just as the results came in. All he was able to do was congratulate the team on a job well done. After all, they had managed to hit the Moon.
