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From: fbr@utastro.UUCP (Frank Ray)
Newsgroups: net.astro
Subject: re: illusion of a larger moon near the horizon
Message-ID: <139@utastro.UUCP>
Date: Wed, 22-Feb-84 09:58:39 EST
Article-I.D.: utastro.139
Posted: Wed Feb 22 09:58:39 1984
Date-Received: Thu, 23-Feb-84 06:06:48 EST
Organization: UTexas Astronomy Dept., Austin, Texas
Lines: 17


George Abell, in the Exploration of the Universe, publ. by Holt,
Rinehart and Winston, writes, pp. 199-200:
	
	"The illusion that the moon (or sun) looks larger near the
	horizon than when it is high in the sky is *not* due to
	refraction [by the atmos.]. Actually, refraction raises the
	lower limb of the moon more than the upper, so that the
	moon really looks smaller and oval near the horizon, not
	larger.  The apparent enlargement of the moon or sun when
	seen near the horizon is a purely psychological effect that
	has been the subject of much discussion and investigation
	by psychologists.

He gives no references to such, however.  By the way, the moon subtends
0.5 deg. of arc.