I have seen these before and always *assumed* it was a direct reflection, or flare, from the solar panels... Derek www.poyntsource.com/New/index.htm -----Original Message----- From: Dale Ireland [mailto:direland@drdale.com] Sent: Thursday, May 29, 2008 7:21 AM To: 'Jeff Umbarger' Cc: SeeSat-L@satobs.org Subject: RE: ISS observation Jeff Interesting theory. Yes we are on the west coast of the US 47.7N 123W. I suppose it could have been lit by a reflection from the ocean farther west and possibly by the white sunlit status clouds over the ocean. It was blazing. I think -5 is conservative because it was essentially daylight. We were having a large BBQ and everyone was ooing and awwing. People who had never seen a bright satellite were hard to convince that it wasn't a reflection off a jet or something. It was way too bright out to even attempt to spot any astronomical object. Venus at its brightest would have taken some effort to find. Dale > -----Original Message----- > From: Jeff Umbarger [mailto:jumbarger2000@yahoo.com] > Sent: Wednesday, May 28, 2008 8:24 PM > To: Gerhard HOLTKAMP; SeeSat-L@satobs.org > Subject: Re: ISS observation > > Maybe if the part of the earth directly below the setting (or > rising) Sun from the ISS point of view was ocean, you might > get a strong secondary light source (the reflected image of > the Sun). But if it were land I would think the it would be a > much weaker light source then the Sun. Interesting spherical > geometry problem - if you assume the earth a mirrored sphere > and the Sun a "few" degrees above the limb of the earth from > the spacecraft position, where would the "reflected" image of > the Sun appear on the earth's mirrored surface from the > perspective of the spacecraft? And at some Sun elevation, > that point is in darkness as seen from the spacecraft. Where > do you live Dale? If it's the West Coast (Pacific), Florida > (Gulf of Mexico), it might explain something for an evening pass. > > Regards, > Jeff Umbarger > Plano, TX USA > > --- Gerhard HOLTKAMP <grd.holtkamp@t-online.de> wrote: > > > > > On Tuesday 27 May 2008 05:13, Dale Ireland wrote: > > > I was amazed last evening at how bright the ISS > > appeared in a pass with the > > > Sun only 2.5 degrees below the horizon, > > practically daylight. I will have to > > > try it on a pass with the Sun still just above the > > horizon. It had to be -5 > > > or better. > > > > > > > On a number of occasions I had the impression that the ISS and in > > years past the Mir were particularly bright just after sunset. > > Maybe is has to do with > > extra reflections from the still illuminated part of the Earth > > surface. (Is there any satellite tracking software which > models this > > effect?) > > > > Gerhard HOLTKAMP > > Darmstadt, Germany ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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