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From: ables@mcc-db.UUCP (King Ables)
Newsgroups: net.astro
Subject: Re: Re: StarDate: June 11 Where the Stars Don't Twinkle
Message-ID: <223@mcc-db.UUCP>
Date: Mon, 24-Jun-85 08:35:46 EDT
Article-I.D.: mcc-db.223
Posted: Mon Jun 24 08:35:46 1985
Date-Received: Wed, 26-Jun-85 06:15:05 EDT
References: <224@utastro.UUCP> <71@denelvx.UUCP>
Organization: MCC (Austin, TX)
Lines: 19

> ... why is it that the stars twinkle but the planets don't.

The reason the planets don't twinkle is about the same reason the
Sun doesn't (although not as exagerated).  The stars are so far
away (thus, so small) that most would appear as just a point of
light if you were in space looking at them.  As that one point
source of the light is seen through the atmosphere, it is affected
as described in the Stardate posting.  A planet, while looking about
the same from the ground, actually is larger to our sight (say from
orbit) and is therefore larger than a single point source of light.
Thus, the process that causes the twinkle isn't as pronounced with
a planet (although, I believe some slight flicker might be perceived
when looking at [for example] Pluto).  The effect is undetectable
with sunlight since the sun appears as such a large object.

O'm French, wha do you think I've got this out-rr-rageous ac-cent?
-King
ARPA: ables@mcc
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