Monday, September 28, 2009
It's been a few days into the aftermath of the discovery of water on the Moon and the effects of the news are quite interesting. Moon advocates are naturally overjoyed by the news, some who were sitting on the fence have decided that this has clinched the deal, while some are digging in their heels and still making the case for Mars. This article is one example, and attempts to make the case that the discovery of water is actually bad news for space exploration, citing the low concentration of water. It also makes an odd reference to the LCROSS mission, saying that due to these findings it "now seems likely that it will only confirm that there are trace amounts of water everywhere on the Moon". That's incorrect - the discovery has nothing to do with the permanently shadowed craters in the region where LCROSS will be impacting, where potential water may have been brought by asteroids and comets, while remaining untouched since then due to the lack of sunlight. So the distribution of water on the Moon is as follows:
-It exists everywhere in certain concentrations in the soil. We have confirmed that it exists within the top 2 mm of soil, but we do not know about deeper layers. For all we know there could be solid blocks of ice a certain depth below the surface.
-Though it exists everywhere in the soil, it is far more prevalent in the higher latitudes, making the equatorial regions even less attractive than before by comparison.
-It is likely to exist within permanently shadowed craters at the poles, and this could be a combination of water brought in from comets etc. as well as the process that creates water within the soil.
The article then concludes with the statement that the possibility of life on Mars will always make it a more attractive destination (if that's so then why not the cloudtops of Venus where life could also exist?), and then ends with "and if it's water you're really after? Mars has more of that too".
No. We're not "after water", we simply need to be able to create enough water that we won't need to ship it directly from Earth. We have plenty of water on Earth so we're not doing this for water. Saying that colonizing the Moon is because we're "after water" is like saying that a group of people that plan to build a new town somewhere are "after roofs" because they are proposing a site nearby where there are enough raw materials to build them. No, the building of these houses would require roofs, but they are not "after roofs". Once one per house is obtained the need is satisfied.
A far better article on the importance of this discovery is here.
It makes a number of good points, such as:
- In the same way that we used to see Mars as being dry and later found out more about it, we are now finding out more and more about the Moon. Ironically, we know much more about Mars than we do about the Moon itself due to the plethora of recent missions to the planet. The discovery of water would have been made much sooner if we had given the Moon more priority after the 1970s.
- Missions to the Moon do not have to cost hundreds of millions of dollars as those to Mars do, and can produce a larger scientific return at only 3 days' journey away (= remote manipulation becomes easier). Even Google's $30 million offering is enough to spur a great many companies into action, whereas this amount would be laughably insufficient for the promotion of a private mission to Mars.
One other interesting article is this one, detailing the sudden increase in confidence and prestige of India's space program. The idea of a probe to the Moon was derided as being impractical and Chandrayaan-1 also ended its mission prematurely, but all of a sudden this discovery was announced and India has been given most of the credit. Not bad for a probe only costing $79 million.
By the way, I've installed a widget on the site showing the current phase of the Moon. Scroll down and look to the right if you haven't noticed it yet.