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Thursdays' Eclipse



Hi all,

This is about Oscar 0 so I hope it is not considered off topic...I'm still
racking my brain! Following the moon and the sun on InstanTrak I notice
that at eclipse, both bodies share the same sub-satellite point (no duh!!).
What has me perplexed though is the fact that the moon's shadow is nowhere
near the moon's ssp during the fact. 

Of course, I already know that the eclipse occurs because the sun, the moon
and the Earth are in line (hence the shadow falls on the Earth, double
duh!). So, if the moon's ssp lies somewhere on the straight line from the
satellite to the Earths' center *and* that line extends on outwards to the
sun at the moment of eclipse, then why is the moon's shadow *not* at the
ssp on Earth's surface.

Another thing, on the InstanTrak screen, eclipse starts east of Brazil and
ends west of Peru whereas in reality, the shadow travelled from somewhere
near the Galapagos Is. to somewhere northeast of the Caribbean. Why is
that? Does it have to do with great circle bearings and the flat map
displayed by InstanTrak? Would the same thing happen if the moon was in a
polar orbit? Would the shadow follow the ssp in that case? Thanks for any
replies and sorry if it is a little off-topic but I couldn't resist.

73 de Rick, HR2KOS




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