8/13 08:81 pm MDT. At sunset, Venus (-3.9) and Saturn (1.1) within one eyepiece view at az 275 alt 8.25. Mecury (-0.6) is about 3 degs PA 109 of Saturn. The Venus Saturn pairing will be at the limits of the telescopic visibility of planets at twilight. May not be observable. Begins a sequence where Mercury sweeps up to the northwest and has conjunctions with Saturn and Venus continuing through 8/22. 8/13 10:34 pm MDT - 8/14 2:25am. Jupiter - Io single planet and shadow transit sequence. (2008 RASC Guide). 8/13 11:00 pm MDT - continuing to 8/18 at 11:00pm each night. C/2008 J1 (Boattini) is within 1.5 degs of del UMi and 3 degs of Polaris. Sweep 3 degs south in dec from Polaris. Moonlight washout likely but decreasing through 8/22. Last reported on ICQ/MPC Comet Brightness list on 8/9 at mag. 9.5, dia. 6' using 25x100 binos. At 11:00 pm MDT position is J200936.62+870125.1. 8/14 04:00 am MDT - continuing to 8/23 each night. C/2007 W1 (Boattini) moves along a line between del Aries towards alf Aries. On 8/14 at 4:00am is within 1 deg of nu Aries, about midway between alf and del Aries and about 7 degs from alf Aries. 8/14 04:00am MDT Pos: J023517.78+205554.2. Last reported on ICQ/MPC list on 8/9 at v7.2, dia. 15'. 8/14 ~4:30-5:00 am MDT - continuing to 8/23. Zodical light between astronomical and civil sunrise. Two SLAS members reported strong zodical light at this time when observing the 8/12 Perseid shower. The 2008 RASC Guide (p. 111) suggests good zodical light beginning on 8/28. 8/14 10:54 pm MDT. (Intermountain only). Occasional Io ECR event. Io "winks" on, exiting the shadow of Jupiter, at some distance from Jupiter's disk. 8/15 10:31 pm MDT. At sunset, Mercury (-0.6) and Saturn (1.1) within one eyepiece view at az 275 alt 6.75. The Venus Saturn pairing will be at the limits of the telescopic visibility of planets at twilight. May not be observable. 8/16 02:00 am MDT - continuing through evening of 8/16. Neptune is at opposition and at brightest (7.8) and largest (2.4") size. RA 21h41.2m Dec -14h14' - 2.0 degs dec slew above gam Cap or 2.0 degs dec and 1 deg ra slew from delta Cap. (Aug ST.; Chart Sep. ST at 63). A slitless diffraction grating, like the Rainbow Optics grating, is a useful tool to distinguish background stars from a planet like Neptune. The stars project spectra; Neptune does not. 8/16 10:55 pm MDT. Jupiter - GRS transit. 8/17 12:09 am MDT (Intermountain only). Occasional Europa ECR event. Europa "winks" on, exiting the shadow of Jupiter, at some distance from Jupiter's disk. 8/18 08:31 pm MDT - continuing through 8/22 at 8:31 pm each night. At sunset, Venus (-3.9) and Mercury (-0.6) within one eyepiece view at az 273 alt 6.27. The Venus Mecury pairing will be at the limits of the telescopic visibility of planets at twilight. May not be observable. 8/18 11:00 pm MDT. C/2008 J1 (Boattini) crosses line between Polaris and del UMi. Sweep alt/az between Polaris and del UMi. Moonlight washout likely but decreasing through 8/22. Last reported on ICQ/MPC list at v9.5, dia. 6.5' using 25x100 binos. 8/19 12:33 am MDT Jupiter - GRS transit. 8/19 12:58 am MDT - 8/20 4:38 am MDT. Ganyemede - single planet and shadow transit sequence. (2008 RASC Guide). 8/19 04:00 am MDT - continuing to 8/23 each night. C/2007 W1 (Boattini) moves along a line between del Aries towards alf Aries. On 8/14 at 4:00am is 5 degs from alf Aries along the alf-del Aries line. 8/19 04:00am MDT Pos: 022844.71+215658.0. Last reported on ICQ/MPC list on 8/9 at v7.2, dia. 15'. 8/21 12:27 am MDT - 8/22 3:40 am. Jupiter - Io single planet and shadow transit sequence. (2008 RASC Guide). 8/21 10:01 pm MDT Jupiter GRS Transit 8/22 08:31pm MDT At sunset, Venus (-3.9) and Mercury (-0.6) within one eyepiece view at az 270 alt 6.40. The Venus Mecury pairing will be at the limits of the telescopic visibility of planets at twilight. May not be observable. 8/23 11:42 pm MDT Jupiter GRS Transit 8/24 10:08 pm MDT Jupiter - End of Io single planet and shadow transit sequence. Io shadow leaves Jupiter's disk. (2008 RASC Guide). - Kurt