Moon recorded Aug. 12 UT in Maryland; prospects for Aug. 13
New: August 13 at 19h UTI travelled east of the DC area to try to get away from some of the haze and high clouds lingering around the city, and west of it. I ended up at Stevensville, on Kent Island where I would have an unobstructed view down to less than 2 deg. above the horizon. That wasn't necessary, since there was still quite a bit of haze, with the Moon disappearing from naked-eye view about 8 deg. above the horizon, from finder view at about the same time, and became very faint with my 8-in. SCT and Watec camera with f/3.3 focal reducer by 4-5 deg altitude, at which point I gave up at about 2:00 UT (I started just a little before 1:00 UT; should have started a little earlier). Although mostly clear, the transparency was considerably worse than it was for the lunar Leonids in Nov. 1999 and 2002. Although not monitoring the view continuously, I did notice some flashes, as follows; they may all be cosmic ray hits or otherwise video noise and spurious: Very approximate UT's (of 2002 Aug. 12 UT) h m s 1:19:25 1:26:33 1:38:28 1:48:00 1:53:50 Especially the last two I'm quite sure are not lunar meteor impacts, as the Moon was in thick haze by then and dimmed several magnitudes. I haven't had a chance to play them back to look at them in detail. They were all in or near Mare Imbrium, which was near the center of my field of view most of the time. The weather satellite image shows some clouds already forming over the Appalachians, with worse weather headed for Ohio and lower Michigan from farther west. As of this afternoon, the clouds have continued to build up, with more now (small daytime clouds) over most of the northeastern USA). So it looks like yesterday's strategy is best for today for this (Mid-Atlantic - n.e. USA) area, that is, go as far southeast away from the mountains as possible. Tentatively, I'll plan to go to Assateague, but the clear sky clock forecast for the whole Delmarva is good, calling for clear skies and pretty good transparency all night for both Tuckahoe State Park and Rehoboth. The forecast for central Maryland is not quite as good, with some clouds late in the evening and relatively poor transparency then. At 0:46 UT Aug. 13 UT, there will be an occultation of 8.4-mag. SAO 139220 (spectral type K2) at cusp angle 63N for the DC/Maryland area, with the Sun alt. -8; that's the best occultation for us tonight and recording that can help calibrate the brightness of any impact flashes that might occur. At 1:35 UT, 8.7-mag. SAO 139230 (spectral type G5) will disappear at cusp angle 43S, with the Moon 13 deg. high; that event will be better for observers farther west where the altitude will be higher (and the event earlier). For the diagram showing where the Perseids will be impacting mainly the northern part of the dark side of the Moon, see http://iota.jhuapl.edu . I will no longer have access to this e-mail soon after sending this message, but can be reached until I leave about 3 pm at my office, at david.dunham@jhuapl.edu , phone 240-228-5609. My car phone has died, so I am using my wife's for tonight, 301-526-5591. Good luck with your Perseid observations, lunar and terrestrial! David