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Old March 28th 13, 11:14 PM
RichardF RichardF is offline
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First recorded activity by SpaceBanter: Mar 2013
Posts: 4
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Quote:
Originally Posted by swc View Post
I noticed a fairly fast paced bright object moving south it went really bright and then dimmed out and I could no longer follow it. About 15 minutes later the same object appeared in the exact same spot only dimmer than the first time and steadily got dimmer till it vanished.
Firstly it's normal that satellites dim out as they go south -- that's because they are moving into the Earth's shadow and when they're not illuminated you can't see them anymore. It's also normal that the brightness varies, and not just for the mirror-like iridium flares. This is because, even when the satellite is in sunlight, you can be looking at the side which is in shadow.

Also, it's extraordinarily difficult to say that a satellite has passed inexactly the same spot, even if you're using the stars as a reference. More likely, you were seeing two satellites in sun-synchronous orbit. These have approximately the same inclination, and so would follow the same path, possibly offset a bit to the east or west. there are loads of such satellites, so this is not uncommon at all.

cheers,
Richard