[extropy-chat] Does the Lunar Surface Still Offer Value for Astro Observatories?

[Robert J. Bradbury]

On Thu, 15 Jan 2004, David Lubkin wrote:

> Back around 1986, Jill Tarter [*] gave a talk at LLNL.  I asked her
> afterwards about the rationale for investing in new Earth-based
> observatories given the prospect of lunar basing.  Her position at the time
> seemed to be that there was little value in this, as compared to what we
> were able to do with Earth-based instruments with inferometry and adaptive
> optics.  I wonder what her opinion is now, post-Hubble.

Hmmm... That is strange as I've seen several proposals for using
the far side of the moon for radio telescopes to avoid interference
from transmitters on Earth.  Furthermore lunar telescopes combined
with Earth telescopes would provide a pretty long baseline for
interferometry.  Adaptive optics does help but only now ~20 years
later is that starting to become an option on the larger scopes
(I suspect that less than half a dozen large scopes have adaptive
optics now.)  One wonders what the cost would be of setting up
a lunar telescope factory if one had a nuclear rocket with heavy
lift capabilities...  But she may be right.  The NGST budget is
$900M in FY '96 $ (over a billion $ now probably).  That is for
4-9m scopes at some distance from Earth.  The same amount ($1B)
is what they are generally talking about for on-the-Earth scopes
in the 30+m class.

Also with respect to inteferometry, though I think they can manage
this with computer integration of radio data from separate locations
(i.e. VLBI efforts), I think all current optical interferometry
observations require a direct tunnel connection between the telescopes
(someone correct this if they know otherwise).

Robert

> [*]  http://www.seti.org/about_us/leadership/staff/jill_t.html