Science reporter, BBC News
The "shepherding spacecraft" will analyse the impact debris
Nasa is set to crash two unmanned spacecraft into the Moon in a bid to detect the presence of water-ice.
A 2,200kg rocket stage will be first to collide, hurling debris high above the lunar surface.
A second spacecraft packed with science instruments will then analyse the contents of this dusty cloud before meeting a similar fate.
The identification of water-ice in the impact plume would be a major discovery, scientists say.
Not least because a supply of water on the Moon would be a vital resource for future human exploration.
There is hydrogen down in that crater, we're going to go dig some of it up
Anthony Colaprete, Nasa
The existence of water-ice in permanently shadowed craters at the lunar poles had previously been postulated by scientists, but never confirmed.
The $79m mission is called LCROSS (the Lunar Crater Observation and Sensing Satellite).
There are two main components: the large Centaur rocket upper stage and a smaller "shepherding spacecraft".
These have been connected since they were launched from Cape Canaveral, Florida, in June.
The shepherding spacecraft is designed to guide the rocket to its target at the Moon's south pole, a shaded 98m-wide depression called Cabeus crater.
Rocket separation
In the early hours of Friday morning (BST), the Centaur and shepherding spacecraft will separate.
At a scheduled time of 1231 BST (0731 EDT), the rocket stage will hit the Moon's south pole at roughly twice the speed of a bullet, throwing an estimated 350 metric tonnes of debris to altitudes of 10km (6.2 mile) or more.
With an energy equivalent to that released by one-and-a-half tonnes of TNT, the collision will carve out a crater some 20m (66ft) wide and about 4m (13ft) deep.
The shepherding spacecraft will follow in the Centaur's wake, descending through the debris plume to hit the lunar surface four minutes after the initial impact.
We will have to be careful to keep some areas as 'protected parks' on the Moon
Bernard Foing, chief scientist, Esa
It will use onboard spectrometers to look for signs of water, hydroxyl compounds (OH), salts, clays, hydrated minerals and organic molecules in the sun-lit plume.
The spacecraft will collect data continuously until it too slams into the Moon, generating a second, smaller debris cloud.
Craters such as Cabeus are permanently draped in darkness and thus very cold, receiving heat only from space and from the Moon's interior (which is not thought to be geologically active).
Here in the lunar "shadowlands", ice - perhaps delivered by cometary impacts - is protected from the Sun's rays and could remain stable over geological timescales.
"If ice is present in the permanently shaded craters... it could potentially provide a water source for the eventual establishment of a manned base on the Moon," said Dr Vincent Eke, from Durham University, UK, who is not a member of the LCROSS team.
Excess hydrogen
But Dr Bernard Foing, chief scientist at the European Space Agency (Esa), said it would be desirable to protect some of this polar ice, if it indeed exists.
"We will have to be careful to keep some areas as 'protected parks' on the Moon. This is so that we could, for instance, send a lander, drill down and obtain a core sample a few metres in depth," he told BBC News.
The red dots show impact points for the two spacecraft in Cabeus crater
"Then we could eventually study the history of delivery of water to the Moon and the Earth."
Dr Foing will work with the LCROSS team to compare the data from LCROSS with those collected when Esa's Smart-1 probe which was brought down on the Moon's surface in 2006.
The idea that reserves of water-ice might persist in these dark craters was given a boost by Nasa's Lunar Prospector mission, which launched in 1998.
By looking at the energy of neutrons coming from the Moon, scientists found excess hydrogen at both poles.
This result does not confirm the presence of water-ice; the hydrogen could be in another form. But if it does exist in the form of ice, data suggest the lunar poles could hold hundreds of metric tonnes.
Anthony Colaprete, principal investigator on the LCROSS mission, said data received in the past few days backed the team's decision to target Cabeus crater.
"There is hydrogen down in that crater, we're going to go dig some of it up," he explained.
Professional astronomers will study the impacts using ground-based telescopes, including the Magdalena Ridge and Apache Ridge Observatories in New Mexico, US, and the MMT Observatory in Arizona.
The Centaur impact plume may be visible through amateur-class telescopes with apertures as small as 10 to 12 inches, mission scientists said.
Earth-orbiting satellites are also geared up to observe the collisions, including the Hubble Space Telescope and the Odin satellite, an astronomy and aeronomy mission led by Sweden.
Paul.Rincon-INTERNET@bbc.co.uk
.Nasa is set to crash two unmanned spacecraft into the Moon in a bid to detect the presence of water-ice.
A 2,200kg rocket stage will be first to collide, hurling debris high above the lunar surface.
A second spacecraft packed with science instruments will then analyse the contents of this dusty cloud before meeting a similar fate.
The identification of water-ice in the impact plume would be a major discovery, scientists say.
Not least because a supply of water on the Moon would be a vital resource for future human exploration.
There is hydrogen down in that crater, we're going to go dig some of it up
Anthony Colaprete, Nasa
The existence of water-ice in permanently shadowed craters at the lunar poles had previously been postulated by scientists, but never confirmed.
The $79m mission is called LCROSS (the Lunar Crater Observation and Sensing Satellite).
There are two main components: the large Centaur rocket upper stage and a smaller "shepherding spacecraft".
These have been connected since they were launched from Cape Canaveral, Florida, in June.
The shepherding spacecraft is designed to guide the rocket to its target at the Moon's south pole, a shaded 98m-wide depression called Cabeus crater.
Rocket separation
In the early hours of Friday morning (BST), the Centaur and shepherding spacecraft will separate.
At a scheduled time of 1231 BST (0731 EDT), the rocket stage will hit the Moon's south pole at roughly twice the speed of a bullet, throwing an estimated 350 metric tonnes of debris to altitudes of 10km (6.2 mile) or more.
With an energy equivalent to that released by one-and-a-half tonnes of TNT, the collision will carve out a crater some 20m (66ft) wide and about 4m (13ft) deep.
The shepherding spacecraft will follow in the Centaur's wake, descending through the debris plume to hit the lunar surface four minutes after the initial impact.
We will have to be careful to keep some areas as 'protected parks' on the Moon
Bernard Foing, chief scientist, Esa
It will use onboard spectrometers to look for signs of water, hydroxyl compounds (OH), salts, clays, hydrated minerals and organic molecules in the sun-lit plume.
The spacecraft will collect data continuously until it too slams into the Moon, generating a second, smaller debris cloud.
Craters such as Cabeus are permanently draped in darkness and thus very cold, receiving heat only from space and from the Moon's interior (which is not thought to be geologically active).
Here in the lunar "shadowlands", ice - perhaps delivered by cometary impacts - is protected from the Sun's rays and could remain stable over geological timescales.
"If ice is present in the permanently shaded craters... it could potentially provide a water source for the eventual establishment of a manned base on the Moon," said Dr Vincent Eke, from Durham University, UK, who is not a member of the LCROSS team.
Excess hydrogen
But Dr Bernard Foing, chief scientist at the European Space Agency (Esa), said it would be desirable to protect some of this polar ice, if it indeed exists.
"We will have to be careful to keep some areas as 'protected parks' on the Moon. This is so that we could, for instance, send a lander, drill down and obtain a core sample a few metres in depth," he told BBC News.
The red dots show impact points for the two spacecraft in Cabeus crater
"Then we could eventually study the history of delivery of water to the Moon and the Earth."
Dr Foing will work with the LCROSS team to compare the data from LCROSS with those collected when Esa's Smart-1 probe which was brought down on the Moon's surface in 2006.
The idea that reserves of water-ice might persist in these dark craters was given a boost by Nasa's Lunar Prospector mission, which launched in 1998.
By looking at the energy of neutrons coming from the Moon, scientists found excess hydrogen at both poles.
This result does not confirm the presence of water-ice; the hydrogen could be in another form. But if it does exist in the form of ice, data suggest the lunar poles could hold hundreds of metric tonnes.
Anthony Colaprete, principal investigator on the LCROSS mission, said data received in the past few days backed the team's decision to target Cabeus crater.
"There is hydrogen down in that crater, we're going to go dig some of it up," he explained.
Professional astronomers will study the impacts using ground-based telescopes, including the Magdalena Ridge and Apache Ridge Observatories in New Mexico, US, and the MMT Observatory in Arizona.
The Centaur impact plume may be visible through amateur-class telescopes with apertures as small as 10 to 12 inches, mission scientists said.
Earth-orbiting satellites are also geared up to observe the collisions, including the Hubble Space Telescope and the Odin satellite, an astronomy and aeronomy mission led by Sweden.
Paul.Rincon-INTERNET@bbc.co.uk
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Source: http://news.bbc.co.uk/2/hi/science/nature/8297811.stm
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P.S.
- Where are the conservationists protesting this destruction of the moon?
- Where's Al Gore with the Global Warming agenda on this issue?
- I guess there are no polar bears on the moon.
- What is the carbon foot print of this crash?
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