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From: steve@jplgodo.UUCP (Steve Schlaifer x3171 156/224)
Newsgroups: net.space
Subject: Re: Uranus's axis
Message-ID: <568@jplgodo.UUCP>
Date: Sat, 8-Feb-86 21:33:52 EST
Article-I.D.: jplgodo.568
Posted: Sat Feb  8 21:33:52 1986
Date-Received: Wed, 12-Feb-86 06:19:04 EST
References: <111@valid.UUCP>
Distribution: net
Organization: Jet Propulsion Labs, Pasadena, CA
Lines: 22

In article <111@valid.UUCP>, jao@valid.UUCP (John Oswalt) writes:
> I know that Uranus's axis of rotation is tilted ~90 degrees from the
> normal, perpendicular-to-ecliptic axis.  This means that the axis
> lies in the plane of the ecliptic, but which way does it point?  
> Does it point at the sun, or is it tangent to the orbit, or some
> angle in between?
Right now, the spin axis is pointing more or less directly at the sun.  As
Uranus moves around the sun, however, the spin axis keeps its same orientation
in space.  This means that in about another quarter of its orbital period
the spin axis will be at right angles to the direction to the sun.
Similarly, in about half of its orbital period from now, the spin axis will
again be pointing at the sun but with the opposite end in the sunward 
direction.  

The orbital period of Uranus (a Uranian year) is about 84 Terran years.
-- 

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