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The Question
(Submitted May 28, 1997)
Would you have by any chance any information on possible
NASA projects as regards observing from the Moon?
Would the dark side of the moon be a good place for a telescope?
The Answer
There are many advantages to putting telescopes on the Moon.
http://snoopy.gsfc.nasa.gov/~lunartel/
proposes an optical telescope on the Moon.
Optical telescopes can be on either the Nearside or the Farside of the
Moon. (The term 'dark side' is no longer used because it
confuses people into thinking that the Sun doesn't shine there. In fact,
the Sun shines on both sides equally.) There is very little atmosphere to
scatter light from the Sun or Earth, so you can use the telescope all day
and all night (14 Earth days each).
Radio telescopes are best placed on the Farside, to block out the radio
noise of
Earth and its increasingly chatty retinue of satellites. Radio bends
around small obstacles so it is harder to block out. Half a mile from the
point where you can no longer see any of Earth would not be enough.
(Besides which, an effect called 'libration' means that Earth wanders
slightly in the sky over the course of a month.) Data communications from
the observatory to Earth should be done by laser through a Lunar satellite
to further avoid noise.
As for whether you would want a manned observatory, probably not. Even on
Earth, there is a tendency to lower the staffing of telescopes for
budgetary reasons, and let the astronomers control the telescopes through
the international computer networks from their own offices. And it costs a
lot more to send an astronomer to the Moon than it does to send her to
Arizona. In addition to being expensive, people are noisy, smelly, and
filthy. Even when she's not kicking dust onto the mirror, she'll be
talking on the radio, stomping around, and venting gas. That's the sort of
thing we're trying to get away from.
A good source of information on NASA's future plans is the
following WWW page:
http://www.hq.nasa.gov/office/oss/strategy/plan.htm
In general, the idea of putting observatories on the Moon
has been around for quite some time. A few years ago, the Bush
administration suggested that NASA look into putting a man on Mars.
One step in this process would be to produce a lunar station
as a testing ground.
Assuming that this lunar station would happen, many astronomers
discussed building observatories on the Moon. In their calculations,
this would be cost-effective only because the prior infrastructure
would already be there.
As it happened, it was later decided that manned missions would be too
expensive, so the lunar station concept was abandoned (at least for
the near future). Without an already existing lunar station, the cost of
building lunar observatories becomes prohibitively expensive.
As I understand it, the only near-future missions to the Moon or
mars are unmanned missions to study the Moon or mars respectively.
Sincerely,
Jonathan Keohane
and David Palmer for Ask a High-Energy Astronomer
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