Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site utastro.UUCP Path: utzoo!watmath!clyde!floyd!harpo!seismo!ut-sally!utastro!fbr 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.