"Eddie - you're clearly obsessed about putting a man tended observatory on the moon for searching for potentially haz. objects.

Now - not once have you actually given a reason why

a) such a facility should be on the moon

b) why it must be man tended."

By briefly looking over this thread, it seems Ed isn't giving you the answers you are looking for, but I like to say a few things about this general topic.
1] I think the Moon could be a preferred location for numerous types of Telescopes- visible light, infrared, radio, etc.
I do think certain things would need to happen before it's a preferred location. I'm not saying that at this moment, detailed plans should be made to have observatory for NEO on the Moon. But if you looking 25 years into the future, I think it would unwise not to consider the Moon as a location.
1a] One thing we need more information on is the "weather" on the Moon. Obviously it does not rain nor is there is wind on the Moon as there is on Earth, but their are other affects which can cause erosion and "weathering" to equipment and infrastructure. It seems to me that the Apollo landing site as well as other missions that left hardware on the lunar surface would provide an opportunity to find out more about the long term affects upon stuff on the lunar surface. A lander sent to any of these locations therefore could be something in which NASA could place a high priority on and it seems their could be some commerical value to choosing these type of location. A typical response to such an idea is the idea of "preserving these historic areas"- it seems to me that there is a fair amount of psychosis associated with the idea of "preserving things in their natural condition". Obviously you could say the vast majority of people would desire this historic site isn't damaged, though being left undisturbed by human beings is an overly simplistic view to take in this matter.
Take for instance, the Titanic. Since the discovery of it's location, one could take the position that it's been damaged. But I think it's instead has been mostly in the direction of it being preserved. Though if Ballard's vision had be taken more seriously by govts it's *possible* there would have been better job done in this regard. In other words, I think if serious people are involved in the process it's possible better solutions could be reached. But despite this I think the net affect of the discovery is more towards preservation- because preservation is more than just "the stuff" and being left "untouched".
1b] Another aspect is the details of the future exploitation of the Moon, we need some laws in this regard. But I cring at mentioning this, because we have tendency to be very unrealistic in this regard- in brief terms, we need laws that encourage exploitation of the Moon AND framework that allows the parties involved to "self regulate" themselves so that all aspects of exploitation are not overruled by some aspects- balance instead of extremism.
1c] Details of costs of using lunar resources in regard to material need for various telescopes. If the only economically viable option is to use only material needed to for telescopes is for material to be shipped from Earth, then any advantage to using the Moon is lessened. For the time being I will focus on advantages which exclude using Moon resources [assuming the worst case of exporting everything needed from Earth]. In regard to Moon we are comparing it to Earth locations and other Space locations [LEO, Sun/Earth L-1, Sun Earth L-2, etc].
The Moon and other space locations doesn't have the Earth's atmosphere which weakens, distorts, and blocks some incoming signals- the Earth's large optical telescope are located at high elevation on Earth to lessen the affect from the atmosphere, and because weather these telescope are required to be in building to protect the instruments. On Earth one's viewing time is restricted, not just by day and nite cycles, but one is interested in one section of the sky, one may have only a few hours to view it- whereas on Moon or Space one could view one particular section of sky for days. On the Moon [other than at polar regions] you have a 14 day Day and 14 day Night. But other than the areas where Sun and Earth are, during the Lunar day the rest of sky is dark [there is no atmosphere scattering the Sun's light]. Because the Moon rotates you have similar problem as Earth as far limited areas of the sky for limited periods, but the Moon is 1/28th of this problem as compared to Earth [and 1/28th the tracking speed required]. Now, Hubble's Day is about 90 minutes, but telescopes at L-points or Lunar pole don't have this day/nite cycle, though lunar polar region has very limited sky as compared to L-points.

The Moon has low gravity. Most of this advantage can realize only if structures are built on the Moon or at least deployed on the Moon. This because bringing things to the Moon will subject it to higher gee forces due to launch. Making large structures such radio telescope on the Moon will require far less structural support and because they are less massive, you could have larger telescopes which capable of being pointed at a target. The low gravity also allow to point at target more efficently- you don't need rocket or gyros in order to point the telescope- instead point them just you do on Earth.