Saturday, November 14, 2009
“The argument that the moon is a dry, desolate place no longer holds water,” says a press release from NASA. A Moon mission launched by the agency has confirmed the presence of water on the moon. The discovery comes a year after a NASA instrument on an Indian lander indicated there were water molecules on the surface of our satellite.
On September 24, 2008 the Indian Space Research Organisation had stated Chandrayaan-1 had discovered water based on readings from NASA’s Moon Mineralogy Mapper, one of eleven instruments carried by the probe. Those results indicated water was widespread in low quantities. That probe, launched in October 2008, had to be abandoned on August 30 when contact was lost with it on the Moon’s surface.
The new mission, called LCROSS, consisted of two separate spacecraft which travelled the 250,000 miles together in June before separating. An empty rocket slammed into the Cabeus crater, near the southern pole, while a small spacecraft stayed behind to take measurements from the plume of debris thrown up, although it too ultimately crashed into Cabeus. Across the United States people spent the night on lawns and in parks hoping to see the impact, on the 40th anniversary of the first Apollo Moon landing, but it was invisible to the naked eye. NASA had predicted a visible six-mile plume; the reality was only a mile high.File:NASA’s Lunar Reconnaissance Orbiter and Lunar Crater Observation and Sensing Satellite leave the launch pad.jpg
The twin impacts on October 9 are now known to have sent 25 gallons of water ice and vapour into the air amongst the debris kicked up from the 60 to 100 foot wide hole produced by the rocket. This amount only accounts for the debris scientists could actually see over the rim, and the remaining debris could contain more water. It is unclear how much water may be distributed across the Moon, although hydrogen at the poles suggests water ice there.
LCROSS stands for lunar crater observation and sensing satellite, which was the satellite’s name, while its rocket companion was called Centaur. It took a month to analyse the spectrometer data from the mission, and efforts are ongoing to determine the composition of the remaining material kicked up out the crater. The whole project cost $75 million.
“We got more than just whiff. We practically tasted it with the impact,” said project co-investigator Peter H Schultz. The material thrown up split into a curtain travelling sideways and a plume that passed the crater’s rim, bringing it into the sunlight for the first time in billions of years. Both contained water. “We are ecstatic,” said project leader Anthony Colaprete.”We didn’t find just a little bit, we found a significant amount.”
Michael Wargo, who heads up lunar research for NASA, said “We’re unlocking the mysteries of our nearest neighbour and by extension the solar system. It turns out the moon harbours many secrets, and LCROSS has added a new layer to our understanding.” It is thought that by analysing the water we can learn of the moon’s history, in a fashion similar to investigating Earth history with ice cores.
University of Maryland physicist Robert Park cautioned that people should not assume that water on the lunar surface would support a colony. “They’ve haven’t found a big reservoir of it,” he said. “I suspect this is just water clinging to the soil particles.”
Buzz Aldrin, one of the first to walk on the Moon when he followed pioneer Neil Armstrong out of Apollo 11, said he was pleased by the news but added that “People will overreact to this news and say, ‘Let’s have a water rush to the moon.’ It doesn’t justify that.” Aldrin wants the US to aim to colonise Mars, but NASA is looking at more lunar trips. Last month a new rocket was tested, and Barack Obama has set up a panel to look at possible Moon missions. George W. Bush had previously proposed a $100 billion programme to put more astronauts onto the Moon. NASA wants to return by 2020 and build a lunar base, allowing astronauts to remain for months at a time.