January 13th Observations of both poles

[Adam Block]

Files beginning with ABLOCK
Name of observer: Adam Block
Email address of observer: abl...@as.arizona.edu
Aperture of telescope: 0.6m
Focal length of telescope: 4755mm
Type of camera used: STL11000 (SBIG)
Camera detector dimensions: 4008x2672 pixels (uncropped)
Exposure information: 0.10 seconds through H-alpha filter
Time and date of exposure: 2009-01-13T04:06:33' /YYYY-MM-DDThh:mm:ss
observation start, UT
Location from which exposure was taken: Mount Lemmon, Arizona

[cano...@yahoo.com]

Adam, Looks interesting but I could not open them on my Windows XP
box. Is there some alternative plugin I can use to open the images?
Or perhaps a smaller file size would work. Thanks - Kurt

[cano...@yahoo.com]

On Jan 13, 6:41 pm, "canopu...@yahoo.com" <canopu...@yahoo.com> wrote:
> Adam, Looks interesting but I could not open them on my Windows XP

> box. <snip> Or perhaps a smaller file size would work. Thanks - Kurt

Adam, Forget it. I was able to open them using API4WIN. - Kurt

[Adam Block]

Great.
Yes, these are just TIF files. This is a small crop of the intrinsic image.
Do you think these will be useful?
Adam

[cano...@yahoo.com]

> Do you think these will be useful?

They are helpful to me personally for learning to recognize the north
polar terrain under various lightings. The northern pole terrain is
harder to navigate since it does not have the same heavily cratered
terrain of the southern polar highlands. Can't say about the LCROSS
team.

I took the liberty of preparing a labeled and cropped version of north
polar image. If you do not want your image used in that way, let me
know and I'll delete it.

ABLOCK_20090113Labeled_kaf.jpg

Mt. Lemon! 600mm of aperture. I'm jealous. :) - Kurt

On Jan 13, 8:04 pm, "Adam Block" <ngc1...@gmail.com> wrote:
> Great.
> Yes, these are just TIF files. This is a small crop of the intrinsic image.
> Do you think these will be useful?
> Adam
>

> On Tue, Jan 13, 2009 at 7:12 PM, canopu...@yahoo.com <canopu...@yahoo.com>wrote:
>
>
>
>
>
> > On Jan 13, 6:41 pm, "canopu...@yahoo.com" <canopu...@yahoo.com> wrote:
> > > Adam,  Looks interesting but I could not open them on my Windows XP
> > > box.  <snip> Or perhaps a smaller file size would work.  Thanks - Kurt
>

> > Adam, Forget it.  I was able to open them using API4WIN. - Kurt- Hide quoted text -
>
> - Show quoted text -

[cano...@yahoo.com]

I posted a corrected version of file "ABLOCK_20090113Labeled_kaf.jpg"
replacing an earlier Jan 14 upload. The new version corrects the
location id of craters Byrd C and Byrd D based on Rukl chart Libration
Zone II.

On Jan 14, 1:24 pm, "canopu...@yahoo.com" <canopu...@yahoo.com> wrote:
<snip>

[cano...@yahoo.com]

Adam,

I have written and submitted a proposed article for the lunar studies
journal _Selenology Today_ about the LCROSS impact. I would like your
permission to use and republish two of your images of the north lunar
pole made in January 2009 that you posted here.

Adam, please let me know if I can have your permission to use and
reproduce your images for publication in _Selenology Today_ at your
earliest convienence.

Clear Skies - Kurt
cano...@yahoo.com

[Jim Mosher]

Kurt,

Readers may find the north polar topography as seen from Earth a bit
easier to understand on the old (but similar resolution) photo posted
earlier by John Sanford:

http://lcross_observation.googlegroups.com/web/Copy%20of%20NPZ1975420Sanford.jpg?hl=en&gsc=8I4VSBYAAADbApJRAzAKi_SjFpjwP985-vghgYgES8zAzJdW7J9-8w

The features you are interested in may be easier to recognize because
this image, taken on film in 1975, shows them tipped more strongly
towards Earth (libration: -4.62 deg in longitude and +6.89 deg in
latitude).

For clarity, the labeled version I have posted at:

http://lcross_observation.googlegroups.com/web/NPZ1975420Sanford_labeled_by_JMM.jpg?gda=o094AlYAAAC-YD7ZnWSsD7fdkYOhVu0XmnVrtGoyQH67jT3_nnElPKx0_2GifC7W2pwhrcrMIurTCEn4eaivFQDkJuF-rBV3WSRz-Detb09CwKfN2BgOPBPhGuxsWDLdLep2NLleRSE

shows John's image at 150% of its original size. IAU feature names
are shown in white; and two possible LCROSS target locations are
indicated in yellow. To better recognize the labeled features, it is
probably helpful to compare the labeled and unlabeled versions.

The IAU feature names are based on a comparison of a synthesized
aerial view of John's photo overlaid on the Clementine basemap and a
comparison of both with the definitive IAU feature name
identifications at:

http://planetarynames.wr.usgs.gov/images/Lunar/lac_1_lo.pdf

The positions of the LCROSS target points relative to the features
visible on John's photo were identified by comparison to the
Clementine basemap which was in turn compared to the positions plotted
on the radar map on page 8 of the Bart 2008 LEAG presentation at:

http://www.lpi.usra.edu/meetings/leagilewg2008/presentations/oct28pm/Bart4050.pdf

Based on the IAU map, Byrd C is a sort of half-crater straddling what
should be the southeast rim of Byrd, and Byrd D is a partial crater at
its poleward end. LCROSS target F is just over the poleward rim of
Byrd D, in what looks like a larger and more circular crater (almost
completely filled with shadow on the IAU nomenclature map).

The small circular craters Main N and Main L are readily visible in
front of Byrd C in John's image, to the upper right of Main. If I
understand your labels, the object you have labeled "Byrd C" in Adam's
less-librated image is actually the unnamed 25-km crater between Main
N and Gioja. For future reference it may be helpful to note that Byrd
C and D are well poleward (and a little to the east) of Main L and N,
and images that are not good enough to show the latter are not likely
to show the former with clarity.

LCROSS target A, as I understand it from the Bart presentation, is a
permanently shadowed area on the floor of Nansen F, just inside Nansen
D (see IAU nomenclature map). I have placed the yellow dot in the
shadowed area next to Nansen D in John's image.

Although the LCROSS project has made little mention about the
visibility of the impact flash from Earth, the fact that the targets
are in permanently shadowed areas does not necessarily mean the impact
sites will be invisible from Earth. When the pole is tipped towards
Earth we see more than an observer on the Sun would, so just like a
radar, we can "see" into the shadowed areas (which we see as black
zones on the poleward sides of sunlit hills and crater rims). Hence,
if the LCROSS impact sites are placed at locations that have been
studied by radar from Earth, then they are most likely "visible" in
John's strongly librated view, although (in the absence of a flash) we
see nothing but shadow there.

Observers should not take this labeled image as an indication that the
centers of Byrd C, Byrd D and LCROSS F always fall along a line skewed
with respect to the limb as it is shown here. As noted above John's
observation was made when the Moon had a strong westerly libration of
-4.62 deg (i.e., with its apparent center of longitude in what is
normally the western hemisphere). When the longitudinal libration is
small, these features fall along a line that is more nearly radial to
the limb, and when the libration is strongly to the east they can be
skewed slightly the other way. Adam's January 13, 2009 observation,
taken with a longitudinal libration of +6.09 deg is an example of this
opposite extreme.

Positive identification of features at the limb is often difficult,
and it would be helpful to have more good photos of the north pole
taken with a variety of librations and lightings. Strongly librated
images like John's are essential for understanding what is being seen
in other cases, such as those that may be planned for the eventual
LCROSS impact.

Another very helpful thing would be to make computer simulations of
what the sunlit poles should look like from Earth based on the
available radar height data, something I myself have done nothing
about so far, but perhaps the LCROSS scientists have.

-- Jim

P.S.: Looking at the latest version of the IAU map linked to above, I
notice that the crater in which LCROSS Target F lies has just been
named "Fibiger" by the IAU, and that the nearby LCROSS Target C (of
the Bart presentation) is now called "Erlanger". The announcement of
these new names was made on January 22nd:

http://astrogeology.usgs.gov/HotTopics/index.php?/archives/351-Nineteen-New-Names-Approved-for-Earths-Moon.html

It's not immediately obvious to me if any part of "Erlanger" is
recognizable in John's photo.

On Jan 23, 3:28 pm, "canopu...@yahoo.com" <canopu...@yahoo.com> wrote:
> Adam,
>
> I have written and submitted a proposed article for the lunar studies
> journal _Selenology Today_ about the LCROSS impact.  I would like your
> permission to use and republish two of your images of the north lunar
> pole made in January 2009 that you posted here.
>
> Adam, please let me know if I can have your permission to use and
> reproduce your images for publication in _Selenology Today_ at your
> earliest convienence.
>
> Clear Skies - Kurt

> canopu...@yahoo.com

>
> On Jan 13, 5:49 pm, Adam Block <ngc1...@gmail.com> wrote:
>  Files beginning with ABLOCK
>
>
>
> > Name of observer: Adam Block
> > Email address of observer: abl...@as.arizona.edu
> > Aperture of telescope: 0.6m
> > Focal length of telescope: 4755mm
> > Type of camera used: STL11000 (SBIG)
> > Camera detector dimensions: 4008x2672 pixels (uncropped)
> > Exposure information: 0.10 seconds through H-alpha filter
> > Time and date of exposure: 2009-01-13T04:06:33' /YYYY-MM-DDThh:mm:ss
> > observation start, UT

> > Location from which exposure was taken: Mount Lemmon, Arizona- Hide quoted text -

[cano...@yahoo.com]

On Jan 24, 12:48 pm, Jim Mosher <jimmos...@gmail.com> wrote:
<snip all>

Thank you for the correction, Jim. It seems my original labeled for
Byrd C and D was right and my "correction" erred. I'll delete the
errorenous copy.

> LCROSS target A, as I understand it from the Bart presentation, is a
> permanently shadowed area on the floor of Nansen F, just inside Nansen
> D (see IAU nomenclature map). I have placed the yellow dot in the
> shadowed area next to Nansen D in John's image.

There is also a small crater within the shadowed area that is shown on
the Clementine polar moasic.
That is what I am guessing is the intended shadowed-crater-within-a-
shadowed-crater specific
target, as opposed generally on the shadowed floor of Nansen F.

Thanks, again. - Kurt

[Jim Mosher]

Kurt,

> There is also a small crater within the shadowed area [of Nansen F]
> that is shown on the Clementine polar mosaic. That is what I am guessing
> is the intended shadowed-crater-within-a-shadowed-crater specific

> target, as opposed generally on the shadowed floor of Nansen F.

I can't see it on the Clementine mosaic I have (the 750 nm basemap).

Although there is no explanation, the image I consulted in the Bart
(2008) presentation showing the LCROSS target positions is, I believe,
a radar map. I think the areas shaded in white are ones that are
expected to be in permanent shadow based on computer calculations
using a digital elevation map and all possible positions of the Sun.
The white area that contains the label "A" is on the floor of Nansen
F, on the side away from the pole and immediately adjacent to Nansen
D, and extending a little towards Nansen C. If that is indeed an area
that is never touched by sunlight, then it should never be possible to
observe surface features there using the Sun as the light source, no
matter what angle you look from. The only way one could see surface
features there would be if one took a long enough exposure to see the
faint illumination from Earthshine and ambient light (which Clementine
did not do); or if the feature was tall enough to stick up into the
sunlight.

Admittedly, I haven't examined all the Clementine imagery of this
area, but in the 750 nm mosaic I see nothing but solid shadow over
roughly one third of the floor of Nansen F, including the entire area
shaded in white in the Bart presentation. The Lunar Orbiter mosaic
used for the IAU nomenclature map similarly shows a large area of
solid shadow -- slightly more extensive than in the Clementine mosaic,
and rotated about 60 degrees clockwise. As it should be, the area
shaded in white in the Bart presentation still appears to be
completely in shadow.

If you could point out the crater-within-a-crater on an image (using
an arrow or something of the sort), then I could better understand
what you are talking about. For such a crater to be visible in an
area that sunlight never strikes I would guess it would have to be a
radar image rather than a Clementine one.

-- Jim

[cano...@yahoo.com]

My bad, I was thinking of an LOIV image but was wrong. - Kurt

On Jan 24, 10:26 pm, Jim Mosher <jimmos...@gmail.com> wrote:
> Kurt,
<snip all>

[cano...@yahoo.com]

On Jan 24, 10:26 pm, Jim Mosher <jimmos...@gmail.com> wrote:
<snip>

> Although there is no explanation, the image I consulted in the Bart
> (2008) presentation showing the LCROSS target positions is, I believe,
> a radar map.  I think the areas shaded in white are ones that are
> expected to be in permanent shadow based on computer calculations
> using a digital elevation map and all possible positions of the Sun.

<snip>

It is from Margot, J. L., Campbell, D.B., Jurgens, R.F. and Slade,
M.A. June 4, 1999. Topography of the Lunar Poles from Radar
Interferometry: A Survey of Cold Trap Locations. Science. 284:1658.
url: http://gssr.jpl.nasa.gov/margotetl1658.pdf

You had mentioned in a prior message that you had gained access to the
2006 Goldstone radar imagery. I understand is located here:

http://pds-geosciences.wustl.edu/missions/lunar_radar/index.htm

Since the four detailed polar images around Byrd are 56mb apiece, I
was wondering if you had accessed this already? See image list in
"INDEX.TAB" and directory

http://pds-geosciences.wustl.edu/geo/arcb_nrao-l-rtls_gbt-4_5-70cm-v1/lrm_90xx/browse/level2/tiff/

- Kurt

[cano...@yahoo.com]

On Jan 27, 2:02 am, "canopu...@yahoo.com" <canopu...@yahoo.com> wrote:
> You had mentioned in a prior message that you had gained access to the
> 2006 Goldstone radar imagery.  I understand is located here:
> http://pds-geosciences.wustl.edu/missions/lunar_radar/index.htm

<snip all>

Jim, I've looked at this and concluded it does not shed any more light
- no pun intended - on the interior of Nansen F. - Kurt

[cano...@yahoo.com]

On Jan 24, 10:26 pm, Jim Mosher <jimmos...@gmail.com> wrote:
<snip>

> If you could point out the crater-within-a-crater on an image (using
> an arrow or something of the sort), then I could better understand
> what you are talking about. For such a crater to be visible in an
> area that sunlight never strikes I would guess it would have to be a

> radar image rather than a Clementine one. - Jim

With respect to whether Crater "A" is Nansen F or a small crater on
the floor of Nansen F, I have uploaded a blow-up image of 62 km
diameter Nansen F from the Clementine 1996 north polar mosiac:

ClementineNansenFHighMag_Kaf20090127.PNG

There are numerous small 1 to 2 km craters on the floor of Nansen F.
I understand (from Arnold (1979) and Bussey et al (2003) that any
crater over 30 meters in diameter can act as a shadowed-crater-within-
a-shadowed-crater cold trap. Although available imagery does not
extend on the floor of Nansen F into the permanently shadowed cold
pocket (on Bart's slide 8), its reasonable to assume that there are
other small 2 km craters in the obscured region.

My best guess (or bet?) is that Crater A is intended to be some 2km
crater and is not a generally potential water bearing layer in Nansen
F. Again, its supposition, the matter is inherently ambiguous, but
that's my best guess and what I was meaning to refer to earlier.

Clear skies - Kurt

[Jim Mosher]

On Jan 27, 1:02 am, "canopu...@yahoo.com" <canopu...@yahoo.com> wrote:
> You had mentioned in a prior message that you had gained access to the

> 2006 Goldstoneradarimagery.  I understand is located here:

>
> http://pds-geosciences.wustl.edu/missions/lunar_radar/index.htm
>
> Since the four detailed polar images around Byrd are 56mb apiece, I
> was wondering if you had accessed this already?  See image list in
> "INDEX.TAB" and directory
>

> http://pds-geosciences.wustl.edu/geo/arcb_nrao-l-rtls_gbt-4_5-70cm-v1...
>
> - Kurt

Kurt,

Sorry about any confusion regarding radar maps of the Moon's poles
that I may have caused.

At this point I can't recall (or find) what I may have posted, but I
asuume it had something to do with radar-derived digital elevation
maps (DEM's), and my wish to simulate views from Earth with them.

I did indeed look at the large (file size) radar maps you mention
being available on NASA's Planetary Data System (PDS) at:

http://pds-geosciences.wustl.edu/missions/lunar_radar/

This site contains radar backscatter maps (not the same as a DEM) of
most of the visible disk of the Moon produced over a three year period
by transmitting radar pulses from the 305-m diameter Arecibo dish in
Puerto Rico and interpreting the signals received ~2.5 seconds later
by a smaller dish in Green Bank, West Virginia. According to the data
labels, the south polar data (spole_pol_... and spole_dep_...) was
acquired on October 19, 2003 at 11:04-12:17 UT when the librations
(from West Virginia) would have been -6.82 (lon)/-6.39 (lat). The
north polar data (byrd_pol_... and byrd_dep_...) was acquired on
October 19, 2006 at 14:11-15:01 UT when the librations would have been
+1.28 (lon)/+0.80 (lat). These maps are said to have a resolution as
fine as 320 m x 450 m at the limb (rather better than optical images
from Earth). Note, however, that the libration at the time of the
north polar map (if the label is correct) was not particularly strong,
so aside from the good resolution it isn't expected to show anything
that couldn't be seen by visual observations (using sunlight) from
Earth.

There is a good write-up explaining how the Arecibo-Greenbank data
were acquired in the "LUNAR_RADAR.PDF" document at the above URL.

The preceding maps were acquired using a 70-cm transmitting
wavelength. Other Arecibo-Greenbank maps using a 12.6 cm wavelength
and reportedly achieving a resolution of 20 m, have were announced at
aobut the same time on an undated webpage at:

http://www.nasm.si.edu/ceps/research/moon/radar_south_images.cfm

That page says the higher resolution data would also be released via
the PDS, but I don't know if it has been, or not.

Based on the Arecibo-Greenbank documentation, my vague understanding
of the way "delay-Doppler" radar maps are made is that a large part of
the Moon is blasted by a single, largely unfocused radio-frequency
pulse. The Moon fragments this into a collection of reflected pulses
that (as received) vary in delay, frequency and intensity. The delay
and frequency shift separately restrict the possible points of origin
of the reflection to specific areas on the Moon (annular rings of
constant distance and velocity), and combining the two assigns each
returned pulse to a unique two-dimensional position in the sky (on the
assumption that the Moon is a perfect constant radius sphere rotating
in accordance with its known librations). To improve signal to noise,
the results from many pulses over several hours are combined. Although
confined to the pieces of surface that are directly visible in the
projection seen from the radar station on Earth (and the "lighting" is
much like that experienced at Full Moon), the reduced data are
typically presented in the form of a standard map projection, such as
a stereographic projection for the poles. What look like shadows in
such re-projected radar maps are areas not visible from Earth (much as
the shadows in optical wavelength images are areas not visible from
the Sun).

To supply the missing third dimension, the delay-Doppler information
received simultaneously at two spatially-separated receiving stations
can be combined interferometrically, and the phase differences
interpreted in terms of height variations at different latitudes and
longitudes on the surface. In this way a height is assigned to each
point in the backscatter map, producing a Digital Elevation Map
(DEM). The only instrument that seems to have this capability is the
Goldstone Solar System Radar (GSSR) which uses three antennas of
NASA's Deep Space Network, one configured as a transmitter, and two as
receivers. Lunar data were first acquired with this system on October
6, 1997 (south pole: 20:30 to 22:10 UT ?), and again on October 19,
1997 (north pole and Tycho: 11:00 to 13:30 UT ?). The data reportedly
has spatial resolution of about 150x150 m, although the polar data
were lumped into 600x600 m bins. It is this data which is unofficially
(?) available at:

http://www.astro.cornell.edu/~jlm/out/pds/

This is the data I was hoping to use to create simulated topographic
views of the Moon's poles as viewed from Earth, and it would also
appear to be this data (or perhaps the 150 m version of it) that is
the ultimate source of the cold trap maps used in the Bart (2008)
presentation to illustrate the locations of the LCROSS impact targets;
although the cold trap maps are illustrated on the backscatter map
(showing reflectances) rather than the DEM (showing elevations).

There is a good write-up about the 1997 GSSR data at (subscription
required):

http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=841991

or as a free reprint on the GSSR website (http://gssr.jpl.nasa.gov/)
at:

http://gssr.jpl.nasa.gov/IEEEtransRemoteSens.pdf

Although there are some ambiguities and inconsistencies in the times
quoted for these maps, it looks like the 1997 south polar data was
acquired when the librations (from the GSSR site) were about -5.95
(lon)/-6.09 (lat); and the north polar data with +3.97 (lon)/+5.67
(lat).

As you have pointed out, a reprint of the /Science/ magazine article
showing the backscatter maps for both poles with and without the cold
traps colored can also be found for free on the GSSR website:

http://gssr.jpl.nasa.gov/margotetl1658.pdf

The GSSR has since been upgraded, and ~90-minute data runs on the
Moon's south pole were repeated on September 13, 2006 (O9:00 - 10:15
UT) and at least two subsequent dates. It is this data which possibly
has resolution to 40 m which was announced with such fanfare at:

http://www.nasa.gov/mission_pages/exploration/mmb/022708.html

but it has never been publicly released, and may never be. The
librations on Sept 13th would have been +8.05 (lon)/-6.16 (lat). A
version of that data set degraded to 600-m spatial and 256 height
levels vertical resolution can be found in an article on polar
illumination by James Fincannon at:

http://gltrs.grc.nasa.gov/Citations.aspx?ID=4166

It is quite possible that still more recent data have been acquired
with both the Arecibo-Greenbank and the GSSR instruments. To the best
of my knowledge both produce backscatter maps; but only the GSSR
produces DEM's (since two receiving antennas are required to do that).


-- Jim

[cano...@yahoo.com]

Thanks for the extensive reply, Jim. Very informative. - Kurt