Saturday, January 31, 2009

ISRO, ESA & NASA meet, talk of Lunar volatiles

Lunar Prospector (1998-1999) analysis of scattered
secondary epithermal Neutrons, indicative of
Hydrogen deposits at the Lunar Poles, most of it,
Dr. Harrison Schmitt points out, well outside the
few permanently shadowed craters

It has been an eventful 100 days for Chandrayaan-I: the lunar orbiter has, yet again, confirmed the presence of iron and picked up X-ray from the Hypatia and the western region of Mare Tranquillitatis during a brief solar flare, and while doing so showed one of its experiments 20 times more sensitive than designers had hoped.

Launched October 22 from Sriharikota, Chandrayaan-I carries 11 science instruments, and of these, five were developed in India while the others were developed by European, American and Bulgarian groups.

Scientists gathered in Bangalore, this week, and asked the question mission planners everywhere are hoping to answer: Do the permanently shadowed polar regions of the Moon contain water-ice?

A group of 70 scientists — from ISRO, NASA and ESA hoped to resolve at a two-day meeting that began in Bangalore Thursday. The meeting held at the ISRO Satellite Centre marked the 100th day since the launch of Chandrayaan-I will discuss data that platform has gathered since arriving in Polar orbit to begin its mission.

The scientists are now focused on identifying “areas of interest” on the lunar terrain for further study, including exploration of the possibility of water-ice, according to ISRO Chairman, G. Madhavan Nair.

“We will now identify areas on the Moon which need to be looked at closer for substances like water-ice. These areas will then be studied with a range of instruments such as the Moon Mineralogy Mapper, Mini Synthetic Aperture Radar and Hyper-spectral Imager,” he said.

The ISRO chief added: “We had an assessment of all the 10 instruments on board the space craft (one of the instruments — the Moon Impact Probe — was designed to crash-land near the poles) and ISRO has confirmed their performance has been excellent so far.” The quality of the images was high, he said.

Before 1994, and the hint of Hydrogen that was first detected at the Lunar Poles by the NASA-DOD mission Clementine, later confirmed by Lunar Prospector, the presence of volatiles had been believed unlikely. Speculation has persisted nevertheless, and from long before Apollo, permanently shadowed craters or valleys at the Lunar Poles were hoped to harbor water ice, most likely of cometary origin.

Sample returns from Apollo and Luna demonstrated the Moon was bone dry, and though this came as no surprise, scientists still had hopes that some sample, however small, might contain a hint of ancient volatiles. Amd yet, very recently, some sample studies have hinted at a memory of water.

Dr. Harrison H. Schmitt, Geologist, former U.S. Senator and Apollo 17 lunar module pilot wrote of the same "gunpowder smell" that he and the other eleven moon walkers detected removing Moon suits after their trips out on the surface. Later, while working at the materials receiving lab in Houston Schmitt reported none of the samples retained that distinct odor. Even those collected and placed in vacuum bottles and sealed on the surface failed, damaged in transit Schmitt speculated or, perhaps because of abrasions on the seals from what is now recognized fully as the pervasive caustic sub-micron dust.

Schmitt speculates that volatiles, reaching the Moon from a variety of sources for billions of years reacted with the Earth's atmosphere, with Oxygen, especially, and dissipated rapidly.

Though some samples have yet to be opened, even after four decades, none of the samples examined so far has escaped exposure.

Schmitt also downplays the likelihood of great abundances of water at the Poles. Even deeply shadowed craters, he says, often are indirectly exposed to sunlight from brightly lit opposing rims and can't escape exposure to more patient cosmic rays.

The mapped data showing the relative abundance of Hydrogen, gathered from Lunar Prospector Schmitt points out show highest concentration at the Poles, without question, and Hydrogen alone would be all that would be needed to obtain Oxygen and perhaps water from Regolith. If Hydrogen, the most abundant element known in the Cosmos, is all that is found at the lunar poles, that importance should not be discounted.


Lunar Mark said...

Have the 'areas of interest' been identified? Are they looking at both poles?

Joel Raupe said...

Svetoslav Alexandrov rightly reported to me he has met the team and those who developed the RADOM-7 instrument, among the 11 on-board Chandrayaan is "not a Russian, but a Bulgarian group."

Editor regrets the error, and appreciates the correction.