Many folks would like to see us back on the Moon and developing its resources.

Tuesday, February 26, 2008

NASA to Release Enhanced Radar Imagery of Lunar South Pole - Comments

NASA to Release Enhanced Radar Imagery of Lunar South Pole - Comments

WASHINGTON -- NASA scientists have obtained the highest resolution
terrain mapping to date of the moon's rugged south polar region and
will discuss the imagery Wednesday, Feb. 27, at the 3rd Space
Exploration Conference in Denver.

Researchers at NASA's Jet Propulsion Laboratory in Pasadena, Calif.,
generated the imagery using data collected with the facility's
Goldstone Solar System Radar. The news media briefing is scheduled for
noon MST in Room 506 of the Colorado Convention Center.

I received a note from Burton Sharpe, one of the co-authors of "THE
MOON - Resources, Future Development and Settlement" in response to my
thoughts that we can't see all of the Moon's South Pole. [See Below]

In my reply to Burt I mentioned some links I found on the Moon's
libration, which is what being able to see more than 50% of the Moon
talks about.
When is a good time to look at the South Pole and when would it be
good to look at the North Pole?

Nice simulation. - LRK -

More information. - LRK -
4b. Libration of the Moon

Where you are on this mother Earth makes a difference too as we have a
tilt with respect to the ecliptic as well.
- LRK -

I mentioned to Burt that when Lunar Prospector was targeted to go into
a crater at the lunar south pole we didn't see any signature for water
vapor which it was hoped would be generated by the impact into where
it was suspected there might be frozen water. I was asked why the
software program 'Starry Night' didn't show an Earth rise if you put
yourself on the surface of the Moon at the south pole. My only thought
was that Lunar Prospector went in on July 31 and the partial lunar
eclipse had occurred on the 28 of July and the Moon was descending
towards the ecliptic and might be going below the ecliptic and Earth's
path around the Sun by the 31st.

I just took a look at an Astronomical Calendar 1999 by Guy Ottewell
and on page 36 he says that on July 29 2:34 UT the Moon's center
reaches descending node through the ecliptic. Doesn't look like by
the 31st it would be the best time for looking UP at the south pole
but rather would be better for looking down at the north pole.

Sooooh, will be interesting to see what comes up on the website on February 27
At noon MST on Feb. 27, terrain maps of the moon's south pole and
other images will be available online at:

Boy, I am sure glad you folks keep me on my toes, wouldn't want the
gray matter to turn to mush. :-)

Thanks for looking up with me.

Larry Kellogg

Web Site:
RSS link:
Hi Larry -- This should be interesting!

The Moon's rotational axis and orbital plane are tilted a total of
about 6 degrees from the ecliptic, so this means that each month an
observer on earth can see, alternately, 6 degrees beyond the pole,
then 6 degrees shy of the pole. The SP region, though, has some very
high and low rough terrain, so the actual relative terrain elevations
are not so easily described. Maybe this will be a bigtime help?

Thanks for your continuing dedication to All Things Lunar! One of the
very best resources around!

Burt Sharpe

In a message dated 2/23/2008 8:19:33 P.M. Central Standard Time, writes:

I didn't think we could see all of the Lunar South Pole from Earth.
Will be interesting to see what they got and how they compare with
what the Japanese are taking with their satellites that are now
orbiting the Moon.
- LRK -
4b. Libration of the Moon

Observers on Earth can see a little more than half the surface of the
Moon, thanks to processes known as "librations." The term comes from
"libra," Latin for scales. This too is the name of a constellation in
the zodiac, supposedly resembling scales, and what we call "pound"
also used to be called "libra," and hence the abbreviation "lb".


Libration is the small oscillation of the Moon about its mean
position. Longitude libration occurs from the Moon's synchronous
rotation and elliptical orbit. Latitude libration is the result of the
Moon's equator being slightly tilted (1.5�) from its orbital plane and
its orbital plane being tilted 5� from the ecliptic. Diurnal libration
is the result of the motion of the observer on Earth as the Earth
rotates. When the Moon is rising in the east we see more of the Moon's
eastern edge and when the Moon is setting in the west we see more of
the Moon's western edge. Maximum librations are 7� 54' longitude and
6� 50' latitude. Also, 1� diurnal libration occures because of motion
of the observer as the Earth rotates.
J. G. Williams , T. P. Krisher, D. H. Boggs, J. T. Ratcliff, and J. O. Dickey
Jet Propulsion Laboratory, California Institute of Technology,
Pasadena, CA, 91109

The analysis of lunar laser ranging (LLR) data strongly detects a
signature of dissipation in lunar rotation. The two possible sources of dissipation are
solid-body tides and interaction at a liquid-core/solid-mantle interface. A simultaneous
fit of both dissipation models [1] finds each cause contributing about half of the dissipation
signature. The separation comes from rotation terms which are a few percent of the
leading dissipation term. Dissipation from tides and core also influences the lunar orbit,
causing secular changes in the orbit period and eccentricity. The latter is useful and
is in better agreement when core dissipation is included,

The lunar equator (mantle) is tilted I = 1.5427� to the ecliptic plane
and it exhibits retrograde precession along the ecliptic with an 18.6 yr period. The
equator and orbit planes precess along the ecliptic plane with the same 18.6 yr
(retrograde) period. Without dissipation, the descending node of the equator matches the ascending
node of the orbit, The most important effect of dissipation on the
lunar rotation is a shift of the node of the processing equator plane (and pole of
rotation) from alignment with the orbit node [2] [3] [4]. Dissipation from both solid-body tides [2]
and core/mantle interactions [3] can cause this phase shift, The shift is most
sensitive to monthly tides and monthly velocity differences between fluid core and mantle. The shift
in the processing pole direction projects into the direction to Earth as a monthly signature.




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