Re: a very bright satellite, or little grey aliens ?

Wasn't it dido22 who wrote:
Hello,

This isn't really a question on astronomy, so please feel free to ingore me, or please point me elsewhere.

I was outdoors last night (Weds 23/July) to watch the ISS go over (due at about 22:40 or thereabouts). It normally flies West - East (approx) and looks a bit like a bright, fast-moving star.

About 10 minutes before the ISS was due I saw a very bright red/orange object travelling in the opposite direction, ie east-west (approx). It was much brighter than the ISS, and much faster. I assume it was a satellite in a lower orbit, and that the red/orange colour was the reflection of the setting sun.

The ISS is in Low Earth Orbit. Anything sufficiently lower than that for the speed difference to be obvious would not be in a stable orbit.

The ISS is by far the biggest satellite. Anything significantly brighter than that would probably be quite large, and we'd know about anything like that.

It's extremely rare for satellites to travel east-west because it's less efficient. You lose the push that you get from taking off from a revolving Earth. There'd have to be a pretty good reason to spend the extra energy to put a satellite into such an orbit, and I can't think of any.

I've never seen a reddened satellite. The geometry of atmosphere and orbit prevents satellites being reddened by the setting sun for more than a fraction of a second, just as they cross into the Earth's shadow. To be continuously reddened due to the sunset, it would need to be inside the atmosphere.

--
Mike Williams
Gentleman of Leisure
.

Relevant Pages

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    (rec.models.rockets)
  • Re: Burt Rutans plans for a manned mission to Mars
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