There is a new official LCROSS page outlining visibilty of the ejecta curtain and suggestions for imaging. LCROSS Citizen Science About Page http://apps.nasa.gov/lcross/about/ They quote without citation an apparent brightness figure of 4 to 6 mpsas and an ejecta curtain size of about 1/3 Jupiter. Mars (3.9 mpsas), Jupiter (5.6 mpsas) and Saturn (6.9 mpsas) have all been imaged at or near the point of occultation by the bright limb of the Moon. Doing some quick internet search, here are some amateur images of a crescent Moon occulting Jupiter: In 1990 http://www.icstars.com/HTML/JupiterMoon/MoonJupiter.html In 2004 http://www.astro.umd.edu/openhouse/gallery/planets/occultations/09nov04.html From what is currently known, if the curtain rises against a background of the night sky and perhaps against the background of the dark shadowed portion of a crater on the sunlit side of the terminator, it should be visible. If it rises, in part, against a background of a sunlit terminator side feature, that part of the ejecta cloud will not be visible. As previously noted, recently released finder maps from New Mexico State University include arcsec scales for the south polar region: http://astronomy.nmsu.edu/rthamilt/LCROSS/media.shtml See the "medium image" at url: http://astronomy.nmsu.edu/rthamilt/LCROSS/media/NMSU_LCROSS_medium.png The "About" page talks about the top of the plume being about 10km in diameter. The image scale on the NMSU finder is 1.78km/per arcsec. So, the top of the plume would be about 17.8 arcsecs across. Newton E, which is marked on the NMSU image, has a catalogue listed diameter of 17km. Note the 20 arcsec scale line on the NMSU image and the catalogue size of Newton E do not match. I'll leave you to make your own conclusions about the approximate visual size of a 10km curtain. The NMSU chart is a fine image and is sufficient to get a rough idea about how big 10km and 30km will appear in the eyepiece or camera on the morning of the October 9 impact. Malapert E, also appears on the NMSU finder, but is not marked, and also has a catalogue diameter of 17km. Here is an image of the south lunar pole that I took in August at f/36 or an efl of about 4600mm using a "small chip" Meade DSI under poor sky and seeing conditions: South Pole Region - Unlabeled http://members.csolutions.net/fisherka/astronote/observed/LCROSS/20090809_11... http://tinyurl.com/mart6v This image can be found in directory: http://members.csolutions.net/fisherka/astronote/observed/LCROSS/20090809_11... The 17km Caebus E and Malapert E are both visible in this image. The above image was taken using this gear: Meade ETX-125 AT 5" (f/15) 1900mm Meade #64 T-Adapter ETX-125EC with a T-Adapter in format 2 has an efl of 2310mm or f/18 (according to the Meade ETX 125 manual) Plus 2x barlow for 4620mm efl or f/36 (4620mm / 125mm) Here's an image I took using a 10" Newt at prime focus with an efl of 1200mm using the same Meade DSI and under extremely poor sky conditions: http://01227941410742638900-a-g.googlegroups.com/web/KFISHER_200812070442.jp... http://tinyurl.com/nb4bwa Little 17km Malapert E is visible to the right of bottom center of the image. Illumination is the opposite side from the August 2009 image. Both images are stacked and highly processed, not raw. The LCROSS Citizen Science "About" page reasons that lower efls will result in a better image because "Higher power is not advisable, which would reduce the brightness per pixel of the plume." Sept 9 - 10 is the next and last imaging opportunity to practice imaging the south lunar pole with 71% illumination nearly the same during the impact. Sept. 9 at 11UT (Sept. 9 at 5am MDT, 77%)) and Sept. 10 11UT (Sept. 10, 5am, 68%): Source: LTVT ephemeris data, topocentric W111.8 N41.8 Date-TimeUT libr_lat lib_long colong illumfrac 20090907 1130 -6.2 -5.5 128 92 20090908 1130 -6.2 -5.5 140.2 85.5 20090909 1130 -6.1 -5.4 152.3 77.3 20091009 1130 -3.5 2.8 158.2 70.9 Impact day 20090910 1130 -5.4 -5.1 164.4 67.7 20090911 1130 -4.4 -4.3 176.5 57.1 20090912 1130 -3.2 -3.3 188.7 45.8 Date-TimeUT Lunar age (days) 20090907 1130 18.1 20090908 1130 19.1 20090909 1130 20.1 20091009 1130 20.6 Impact day 20090910 1130 21.1 20090911 1130 22.1 20090912 1130 23.1 For Sept. 9 and 10 at 11UT times (Sept. 9 at 5am MDT, Sept. 10 at 5am MDT) in Salt Lake City, the Moon will be an altitude much closer the circumstances of impact - around 70 degrees. There will be one more 71% illumination opportunity later in September, but from the opposite side from the Oct. 9 impact. Clear Skies - Kurt