The USNO table for SLC shows astronomical twilight at 05:02 on October 9.  This will be cutting it close, particularly, as I believe, that at the last minute the LCROSS Team will slip the impact time to bias the impact +4 hours to put the Moon directly over the Keck and IRTF in Hawaii.  The LCROSS Team has always stated that their desire has been to have Keck and IRTF as the primary ground based scopes. But, the matter is inherently uncertain.  If the weather is bad over Hawaii, the LCROSS Team has some control over the exact moment of impact and may bias it towards the New Mexico scopes - again, where the weather is bad in Hawaii.  Even if none of the above pans out,  the LCROSS Team will be streaming live Ranger-era style video from the craft as it does the kamikse run - watching the booster impact from above.  In addition to having a nice breakfast, you can also watch the impact in the spacecraft driver's seat so to speak. Less clear is whether on the June 23 gravity assist flyby of the Moon is whether the LCROSS team will be streaming live video.  At a news conference earlier this week, one of the project team members indicated that they would be. Because of these uncertainties, I have not been recommeding a formal club event built around LCROSS. It may be possible to build a club event around acquiring images of the Centaur booster in cruise orbit over the next three months.  On the other hand, there have only been two major U.S. missions to the Moon since Apollo (Clementine and Prospector).   A once in 10-20 year event is worth monitoring. Finally, the club may wish to consider the potential for increased general public interest in lunar observing over the summer.  LRO will reach lunar orbit in a few days and after a shake-down period will start streaming back HD images from an 80 km orbit with a nearly live release schedule - like the images from the Mars Rovers and MRO.  These images will be so stunning (1 meter resolution) and will be hyped by the NASA p.r. machine such that it will hopefully pique the interest of a new younger generation of U.S. observers.  (1% of the images will have 50cm resolution.)   My suggestion to club members is to dust of your lunar maps now and start refreshing your recollection of crater names for use at July and August star parties. Clear Skies - Kurt P.S. - USNO Astrometric server basic sunrise/sunset data for Oct 9 ================= Sun and Moon Data for One Day The following information is provided for Salt Lake City, Salt Lake County, Utah (longitude W111.9, latitude N40.8):         Friday           9 October 2009        Mountain Daylight Time                                  SUN         Begin civil twilight       7:05 a.m.                         Sunrise                    7:33 a.m.                         Sun transit                1:15 p.m.                         Sunset                     6:56 p.m.                         End civil twilight         7:23 p.m.                                          MOON         Moonrise                   9:40 p.m. on preceding day         Moon transit               5:38 a.m.                         Moonset                    1:35 p.m.                         Moonrise                  10:43 p.m.                         Moonset                    2:28 p.m. on following day  Phase of the Moon on 9 October:   waning gibbous with 68% of the Moon's visible disk illuminated. Last quarter Moon on 11 October 2009 at 2:56 a.m. Mountain Daylight Time. ========== P.P.S. - Unlike the Kayuga impact video (that Patrick linked a couple of days ago) and SMART-1,  LCROSS is engineered as a high-angle (+67 degrees), high-energy impact.  Kayuga and SMART-1 were simple orbit deterioration impacts at less than 10 degrees - where the impact energy is dispated due to the impact angle and the impact cloud sprays horizontally and would have been expected to rise into the sunlight.