To correct my prior post, the faint background features seen in the image are not illuminated by backlighting; they are illuminated by various low angle (0.3 degrees) direct sunlight. The feature in the background most probably is a highland between Shoemaker and Shackleton and not Shackleton, as previously stated. Further analysis of the pixel values between faint indicates a differential magnitude between the foreground bright spot next to Malapert E and the faint background features of about 1.6 mags. A background info panel is available at: http://members.csolutions.net/fisherka/astronote/observed/LCROSS/20090809_11... http://tinyurl.com/mlmseo I have done a little experimentation with co-imaging reference stars and the Moon's disk to establish the differential magnitudes of faintly illuminated features and background sky brightness washed out from lunar glare. In the next lunation, I'll be trying to refine that test to determine glare magnitudes of the background sky above Malapert E. The results of those tests should help in finding some imaging magnitude boundaries for the faintest eject cloud that can be imaged with amateur class scopes and cameras. Clear Skies, Kurt ----- Original Message ---- From: Canopus56 <canopus56@yahoo.com> To: Utah Astronomy List Serv <utah-astronomy@mailman.xmission.com> Sent: Wednesday, August 12, 2009 10:17:44 PM Subject: Re: [Utah-astronomy] LCROSS: South Pole LCROSS target zone imaging 2009-08-09 11_23UT I had a few moments to image last night and made a technically poor image (20090811 at 0937UT) using a Meade ETX 125 at about f/30 and an older DSI-ProI. The image captures lunar south pole shadowing analogous to what will appear on the morning of the LCROSS impact. For illumination and sun-angle comparision, I also took a prior image on August 9 at 11:37UT: Lunar libration data for images and impact Source: LTVT ephemeris data, topocentric W111.8 N41.8 Date-TimeUT libr_lat lib_long colong illumfrac sunalt_MalpertE 20090811 0937 -6.1 -6.5 157.1 74.4 -0.5 20091009 1130 -3.5 2.8 158.2 70.9 1.6 20090809 1123 -5.2 -6.0 133.7 89.4 2.9 Date-TimeUT Lunar age (days) 20090811 0937 20.3 20091009 1130 20.6 20090809 1123 18.4 Item I. - South pole image 20090811 at 9:37UT http://members.csolutions.net/fisherka/astronote/observed/LCROSS/20090811_09... http://tinyurl.com/p3bdlk This image is a single frame - no stacking or deconvolution - and has been unsharp masked and gamma processed. While technically below the prevailing acceptable quality for amateur lunar imaging standards, it does record illumination and shadow conditions analogous to the LCROSS impact set for Oct. 9, 2009. Item J. - Same as item I but LTVT labeled with craters http://members.csolutions.net/fisherka/astronote/observed/LCROSS/20090811_09... http://tinyurl.com/pnmgta Item K. - Same as item I but hyperexposed to see if more detail could be extracted from the "Malapert dark hole". http://members.csolutions.net/fisherka/astronote/observed/LCROSS/20090811_09... http://tinyurl.com/qty3q8 (The Item K image is a single frame - no stacking or deconvolution. A stacked set of images also failed to bring out any more detail than that seen in the single frame image.) In the hyperexposed version, a snipet of the Faustini crater rim can be seen to the right of and below Malapert E. (Compare Item K to the best of the March 2009 south pole images.) Visually, this Faustini crater rim snipet was quite easily seen with 125mm of aperture. All images are in directory http://members.csolutions.net/fisherka/astronote/observed/LCROSS/20090811_09... Unlike my August 9 image, hyperexposing the Malapert "dark hole" did not bring out any additional detail. Compare Item K above with my Aug. 9 hyperexposed image: E. - Aug. 9 experimental hyperexposure - brings out hidden detail in the "Malapert dark hole". http://members.csolutions.net/fisherka/astronote/observed/LCROSS/20090809_11... http://tinyurl.com/ncjgcb I attributed the difference in the effectiveness of pulling detail out of a shadowed region to sun angle. On Aug. 9 the Sun angle at Malapert E was 2.9 degs. I believe at this angle, the Sun was also hitting the hidden backside of Leibnitz B and created a backscatter of light that faintly illuminated the interior of the Malapert "dark hole". On Aug. 11, the sun angle at Malapert E was -0.5 degrees, and there is no backscatter off the backside of Leibnitz Beta into the Malapert "dark hole". I was unable to image on the morning of the 12th, but observed visually at 2009-08-12 14:00UT during daylight. By then, a characteristic "dark canyon" for this colongitude (172 degs) leading from Moretus to Malapert had formed. The "hole" consists of Short and series of depressions lunar east of Newton B, M, G, A and ending with Newton B. This extended dark canyon trails lunar south down to the Malapert dark hole. It can be seen in Westfall's Atlas in plates 174-S and 179-S. The imaging lesson learned comparing the Aug. 9 and 12 images are that faint features can be extracted by hyperexposure notwithstanding lunar glare emitted from features on the bright side of the terminator. This result relates to two hypothesized impact ejecta curtain scenarios for the October 9 LCROSS impact. The first ejecta cloud scenario is the conservative LCROSS team planning assumption - a 10km wide by 5km high lampshade figure with a 2.5 km line rising above the rim of a permanently shadowed crater rim and being visible from Earth. The second ejecta cloud scenario is a more liberal hypothetical assumption of a 20km by 20km curtain capable of reflecting light that can be seen by a 254mm (10 inch) aperture amateur class telescope from Earth. For scale, the diameter of Malapert E is 17km. Using my Aug. 11 image, I added scaled ejecta cloud curtains for these two hypotheticals. Using 17km diameter Malapert E as the image scalar, the Aug. 11 image works out to an image scale of about 600 meters per pixel. Here's the Aug. 11 image with scaled figures for the two ejecta cloud hypotheticals: Item L. - Sames as Item I with scaled ejecta cloud hypotheticals - brightness of the cloud is abitrary http://members.csolutions.net/fisherka/astronote/observed/LCROSS/20090811_09... http://tinyurl.com/prdaku The luminance of the two scaled ejecta curtains is arbitary and is not intended to represent the actual, but presently unknown, brightness of the LCROSS impact ejecta curtain. The implication of these hypothetical cloud scales for the hyper-exposure imaging method is that the bright-border effect seen in the Aug. 9 image indicates that a 10km by 2.5km high ejecta curtain would be overwhelmed by the hyper-exposure border glare. See the following images showing the hyperexposure border glare where the southern lunar limb outline meets the dark sky - E. - Aug. 9 Experimental hyperexposure - brings out hidden Shoemaker in "Malapert shadow hole" http://members.csolutions.net/fisherka/astronote/observed/LCROSS/20090809_11... http://tinyurl.com/ncjgcb Item K. - Aug. 11 Experimental hyperexposure. Same as item I but hyperexposed to see if more detail could be extracted http://members.csolutions.net/fisherka/astronote/observed/LCROSS/20090811_09... http://tinyurl.com/qty3q8 Conversely, a 20x high ejecta curtain would rise high enough above the hyperexposure border glare to be captured by imaging - assuming the ejecta curtain reflects enough sunlight to be detected from Earth. The above discussion is not intended to say anything about the likelihood of visually observing the ejecta curtain. As noted above with respect to the August 11 image, the Faustini crater rim snipet was quite easily seen visually with 125mm of aperture. In the hyperexposure Aug. 11 image, the Faustini rim snipet is barely visible. Clear Skies - Kurt References: Malapert E diameter http://planetarynames.wr.usgs.gov/jsp/FeatureNameDetail.jsp?feature=71175