I think it's a bit of a p.r. exaggeration. Total cross-sectional area will roughly double when the remaining large components are added to the ISS. That corresponds to a brightess change of about one magnitude. Not really a big deal. So can you see it in daylight? Sure. And you can now, too, but you need excellent eyes, exact knowledge of its position in the sky for every moment of time, and crystal-clear skies. There's another way to analyze this. As far as its visual properties are concerned, the ISS is directly analogous to an aircraft in sunlight --but one without a contrail behind it. How large an aircraft does it correspond to? The ISS is about 250 feet across (very roughly) at a height of about 250 miles. So for a comparable aircraft, consider one that is 2.5 feet across at at an altitude of 13,000 feet (2.5 miles). That will have the same angular size as the ISS. Do you think you can see a model airplane, or a seagull, flying above you at an altitude of 13,000 feet in daylight? Sure you can... with excellent eyes, exact knowledge of its position, and crystal-clear skies. The odds are against it. -FER 42.0N 87.7W, or 41.4N 72.1W. www.HistoricalAtlas.com/lunars ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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