At 07:17 01/12/00 -0500, Penny Fischer wrote: >Hi Satters, > >I have not seen predictions yet on the estimated brightness of the ISS after the solar >panel deployment this Sunday. I only heard it's going to be the brightest artificial >orbiting body. Anyone have any idea how bright it will get? > There have been numerous reports on how the brightness of the ISS will increase markedly after the addition of the huge solar panels during the present shuttle mission. It should be pointed out, as many will already be aware, that ISS is one of the brightest objects in the sky, even before the installation of these massive 'wings'. It is frequently observed as brighter than first magnitude, sometimes even in the range of negative magnitudes. The solar panels are designed to convert the sunlight falling on them into electrical current to power the operation of the ISS. They therefore absorb the vast majority of the incident sunlight and reflect very little. This is why they appear black, or at least very dark in photographs. Furthermore, the panels will be aligned with the Sun so they present the maximum area towards the incoming radiation. Any reflection is therefore likely to be directly back towards the Sun and not downwards toward to observer on the surface of the Earth. There is even the possibility that the brightness of ISS might be diminished, since these panels will cast vast shadows, intercepting some of the sunlight that might have gone on to reflect off the (cylindrical) modules that are already part of ISS. Just what effect this 'shadowing' has remains to be seen, but I for one do not anticipate a major jump in the brilliance of ISS after this mission is completed. It may however be easier to spot a distinct 'shape' under even moderate magnification. ------------------------------------------------------------------------ Best wishes, Russell Eberst Station 2420: Latitude 55.9486N, Longitude 3.1383W, height 150ft = 46m. 181105 Observations ------------------------------------------------------------------------ ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www2.satellite.eu.org/seesat/seesatindex.html
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