Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!seismo!ut-sally!utastro!ethan
From: ethan@utastro.UUCP (Ethan Vishniac)
Newsgroups: sci.space
Subject: Re: Volcanism (from net.space)
Message-ID: <1385@utastro.UUCP>
Date: Wed, 5-Nov-86 10:38:04 EST
Article-I.D.: utastro.1385
Posted: Wed Nov  5 10:38:04 1986
Date-Received: Wed, 5-Nov-86 22:29:22 EST
References: <3400001@wdl1.UUCP>
Organization: U. Texas, Astronomy, Austin, TX
Lines: 22
Summary: yes

In article <3400001@wdl1.UUCP>, gerolima@wdl1.UUCP (Mark Gerolimatos) writes:
> (duplicate posting from net.space...)
> 
> I was reading some stupid Time/Life book on the solar system, when
> I ran across something on Io. The line mentioned that Io's volcanism
> is not a result of radiation, as on earth.
> 
> Can someone please explain what they meant by volcanism begin the
> result of radiation? Perhaps they meant in the form of heat from
> the core?

You have it.  The Earth's core is hot as a result of radioactive decay
of heavy atoms.  (There is also some contribution from the release of
latent heat as material gradually solidifies).  Io's core is too
small for this to work (also Io is made of lighter stuff).  Its
core is heating by tidal friction.
-- 
"More Astronomy                Ethan Vishniac
 Less Sodomy"                  {charm,ut-sally,ut-ngp,noao}!utastro!ethan
  - from a poster seen         ethan@astro.AS.UTEXAS.EDU
    at an airport              Department of Astronomy
                               University of Texas