Washington - The element hydrogen - a key ingredient in water - is more widespread than expected at the moon's south pole, scientists said Thursday. NASA scientists announced the first data sent back to Earth from the Lunar Reconnaissance Orbiter (LRO), a satellite that will spend the next year making the most detailed maps yet of the moon's surface to prepare for man's eventual return.
The craft is outfitted with instruments to provide a range of scientific data about the moon and to take photographs.
Astronomers had hoped to determine whether water could be hidden in the shadowy craters of the moon near its poles, where a lack of sunlight would prevent ice from evaporating. But the early results showed that hydrogen was spread across the south pole, not just in the craters, said Richard Vondrak, a scientist for the LRO project.
An earlier lunar satellite found high levels of hydrogen in the atmosphere near the poles, a hint that water could be present.
Another of the craft's instruments showed the craters could also be the coldest spot in the solar system.
One instrument that takes pictures of the lunar surface found that temperatures at the moon's south pole range from 100 degrees Kelvin (minus 173 degrees Celsius) at night to 380 Kelvin (107 degrees Celsius) during the day, or hotter than the boiling point of water.
But in the permanently shadowed craters, where scientists hope to find signs of ice, temperatures never exceed 35 degrees Kelvin (minus 238 degrees Celsius), Vondrak said.
That is colder than any other region in the solar system that has been identified - even far-flung Pluto, he said.
More analysis and data are need to determine the significance of the finding and why the hydrogen is in some areas and not others, Vondrak said, noting that the element was not present in all of the craters.
One possibility is that the hydrogen was deposited on the moon by a comet or some other incident and became buried just under the surface, keeping it from evaporating, scientists said.
Part of the answer could come October 9, when another craft, the Lunar Crater Observation and Sensing Satellite (LCROSS), is to crash into the moon, sending up a cloud of dust that astronomers will analyze for evidence of water and other particles.
The two-part mission with LRO and LCROSS is just beginning, with LRO set to orbit the moon at a low altitude for at least the next year.
"The moon is starting to reveal her secrets, but some of those secrets are tantalizingly complex," Michael Wargo, NASA's chief lunar scientist, told reporters.
