Apollo Landing Sites Scouted by Hubble

I know it has been discussed here in the past, but since HST's viewing
of several lunar sites, including the Apollo 15 & 17 landing sites,
made recent news I thought I'd check on this. How good would Hubble's
resolution be for the Apollo sites? I'm sure it could see the areas of
displaced soil from the lunar rovers especially around the descent
modules, but could it discerne the descent modules themselves? How
about the various man-made craters? I'd think since we know the
circumstances and dates of these, that they would be prime viewing
targets.

wrote in news:1130206754.977446.167050
@z14g2000cwz.googlegroups.com:

I know it has been discussed here in the past, but since HST's viewing
of several lunar sites, including the Apollo 15 & 17 landing sites,
made recent news I thought I'd check on this. How good would Hubble's
resolution be for the Apollo sites?

Not very high, since the moon moves too fast for HST's fine guidance system
to track accurately.

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In message , Jorge R. Frank
writes
wrote in news:1130206754.977446.167050
:

I know it has been discussed here in the past, but since HST's viewing
of several lunar sites, including the Apollo 15 & 17 landing sites,
made recent news I thought I'd check on this. How good would Hubble's
resolution be for the Apollo sites?

Not very high, since the moon moves too fast for HST's fine guidance system
to track accurately.


That isn't the issue. It's simply that Hubble is too small by a couple
of orders of magnitude to resolve the sites. You need a mirror several
hundred meters across.
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Remove spam and invalid from address to reply.

In article .com,
wrote:
...How good would Hubble's resolution be for the Apollo sites?

As JRF has already noted, Hubble can't track the Moon well enough to
get really high resolution there. In any case, there is a quick rule
of thumb:

resolution = distance * wavelength / diameter

Depending on your exact definition of "resolution", there may also be a
constant involved, but it's not too far away from 1, so it can be ignored
for a rough estimate. This resolution is the fundamental limit set by the
wave nature of light; imperfections in optics and detectors can make it
worse but not better.

Hubble is a 2.4m telescope if I recall correctly, and it's observing at a
distance of maybe 380,000km. If we say it's using 400nm light -- right at
the short end of the visible spectrum -- and pay careful attention to the
units, its resolution works out to be around 65m. That means that if you
want to be able to make out the shape of an object, the object has to be
at least 200-300m across.

Resolution doesn't always tell the full story. You can detect a small
bright object on a dark background (or vice-versa) even if it's well below
the resolution limit, because even when you average its brightness
together with a chunk of the background, it's still brighter than plain
background. But you can't make out its shape; it'll just be a speck.

I'm sure it could see the areas of
displaced soil from the lunar rovers especially around the descent
modules, but could it discerne the descent modules themselves?

Given the above numbers, even if Hubble could somehow operate at full
resolution, at most you'd see a speck or two that would be noticeable
only if you knew exactly where to look. You wouldn't really get any
hint of shape.

How about the various man-made craters? I'd think since we know the
circumstances and dates of these, that they would be prime viewing
targets.

Unfortunately, even the S-IVB craters are only about 40m across.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

On Tue, 25 Oct 2005, Henry Spencer wrote:

In article .com,
wrote:
...How good would Hubble's resolution be for the Apollo sites?

As JRF has already noted, Hubble can't track the Moon well enough to
get really high resolution there.

Can it play tricks such as clocking the CCD array out at the same rate the
Moon is moving through the field of view?

--
Bill Higgins | "His SF tended to be thinly disguised
Fermilab | physics papers -- but then, his physics papers
Internet: | tended to be thinly disguised SF."
| --Jordin Kare on Robert L. Forward (1932-2002)

KECK can do better than HST. Hells bells folks, TRACE can do as good as
HST. Since the moon is so nicely illuminated and, because the moon has
only a slight bit of a mostly crystal clear sodium, argon and radon
atmosphere, thus the KECK CCD scan rate can be fairly high, as well as
the applied CCD need not have such a terrific DR to work with.
Therefore the 2.2 micron/pixel CCD can be applied, and stacking can
also be employed along with each pixel reduced to as little as 1% of
it's full coverage, thus technically making the CCD pixel equal to a
0.22 micron. Add another ten power optical magnification and we should
be nearly able to see those foot prints.

The advantage that HST has is that it'll do by far the best earthshine
illuminated moon shots with photons to spare. Of course, since portions
of those Apollo remains should have an albedo of 80+% as otherwise
surrounded by a carbon/soot dirty brown worth of an 11~12% albedo moon
should make for whatever's artificial stand out like a sore thumb.
~

Kurt Vonnegut would have to agree; WAR is WAR, thus "in war there are
no rules" - In fact, war has been the very reason of having to deal
with the likes of others that haven't been playing by whatever rules,
such as GW Bush.
Life upon Venus, a township w/Bridge & ET/UFO Park-n-Ride Tarmac:
http://guthvenus.tripod.com/gv-town.htm
The Russian/China LSE-CM/ISS (Lunar Space Elevator)
http://guthvenus.tripod.com/lunar-space-elevator.htm
Venus ETs, plus the updated sub-topics; Brad Guth / GASA-IEIS
http://guthvenus.tripod.com/gv-topics.htm

KECK can do a whole lot better than HST. Hells bells folks, TRACE can
do as good as HST. Since the moon is so nicely illuminated and, because
the moon has only a slight bit of a mostly crystal clear sodium, argon
and radon atmosphere, thus the KECK CCD scan rate can be fairly high,
as well as the applied CCD need not even have such a terrific DR to
work with. Therefore the 2.2 micron/pixel CCD can be applied, and
stacking can also be employed along with each pixel format reduced to
as little as 1% of it's full coverage, thus technically making the CCD
pixel equal to that of a 0.22 micron. Add another ten power optical
magnification and we should be nearly able to see those foot prints.

The advantage that HST has is that it'll accomplish by far the best
earthshine illuminated moon shots with photons to spare. Of course,
since significant portions of those Apollo remains should have an
albedo of 80+% as otherwise surrounded by a carbon/soot dirty brown
worth of an 11~12% albedo moon should make for whatever's bright and
shiny as artificial stand out like a sore thumb.

The problem is, it seems that quality films can still way outperform
CCDs in such low DR demanding situations, and the second problem is
that it's taboo/nondisclosure for either of the big KECK instruments to
be looking at the moon. Imagine that, a "do not look" and "do not tell"
policy that sucks and blows KECK style of brown-nose status quo or
bust.
~

Kurt Vonnegut would have to agree; WAR is WAR, thus "in war there are
no rules" - In fact, war has been the very reason of having to deal
with the likes of others that haven't been playing by whatever rules,
such as GW Bush.
Life upon Venus, a township w/Bridge & ET/UFO Park-n-Ride Tarmac:
http://guthvenus.tripod.com/gv-town.htm
The Russian/China LSE-CM/ISS (Lunar Space Elevator)
http://guthvenus.tripod.com/lunar-space-elevator.htm
Venus ETs, plus the updated sub-topics; Brad Guth / GASA-IEIS
http://guthvenus.tripod.com/gv-topics.htm

http://www2.keck.hawaii.edu/news/old...40history.html
But it was earth's moon projected onto a portable movie screen that
took everyone's breath away, said DiVittorio. Even with the screen,
only a fraction of the moon could be shown. Still, after a few quick
computations, DiVittorio determined that the observers saw earth's moon
as if viewed three feet back from a spaceship window with the spaceship
orbiting about 300 miles above the surface of the moon. "It was
spectacular! It was first time an organized group has used a 10-meter
telescope in this way. And for some of the summit crew, it was their
first time ever looking through a telescope. And it was a 10-meter!
-

Silly me, it seems that I'm thinking outside the box again, thinking
that via another 10X optical magnification and having projected and
thus exposing that image onto a few sheets of positive print film might
get a little grain per grain embarrassing.

Otherwise doing a GOOGLE search for whatever's KECK and MOON comes up
fairly image empty handed, as though our once upon a time icy
proto-moon has noting worthy to offer.

Of course, a good shot as obtained via KECK of having either Mars or
Jupiter just off the lunar horizon in full/natural colour might also be
a little worthy of folks asking why our moon offers such a dark and
downright dirty/soot golden brown sort of nasty terrain, with some of
the zones contributing an extremely deep blue attribute, none of which
was ever recorded from the surface of the moon. In fact, a good many of
the NASA/Apollo Kodak moments on the deck were of nearly white-out
zones of 55+% albedo for as far as their unfiltered Kodak eye could
see. Would you folks like a few of those examples, including those
apparently of retroreflective moon-dirt shots as accomplished perhaps
via Xenon lamp as well as having the Xenon spectrum to work with
instead of what the raw solar illumination spectrum that should have
been the case, as taken directly from the official film archives?
~

Kurt Vonnegut would have to agree; WAR is WAR, thus "in war there are
no rules" - In fact, war has been the very reason of having to deal
with the likes of others that haven't been playing by whatever rules,
such as GW Bush.
Life upon Venus, a township w/Bridge & ET/UFO Park-n-Ride Tarmac:
http://guthvenus.tripod.com/gv-town.htm
The Russian/China LSE-CM/ISS (Lunar Space Elevator)
http://guthvenus.tripod.com/lunar-space-elevator.htm
Venus ETs, plus the updated sub-topics; Brad Guth / GASA-IEIS
http://guthvenus.tripod.com/gv-topics.htm