Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/5/84; site mcc-db.UUCP Path: utzoo!watmath!clyde!bonnie!akgua!whuxlm!harpo!decvax!genrad!panda!talcott!harvard!seismo!ut-sally!mcc-db!ables 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 UUCP: {ihnp4,seismo,ctvax}!ut-sally!mcc-db!ables