On Wed, 15 Dec 1999 you wrote:

> i am researching pluto as a school report and cannot find any information on
> the gravitational pull. my report is due on dec. 20th.
> if you don't know the answer, maybe you can tell me where else i can look.
> thank you,
> amy

Hi Amy,

I found a web page with information on Pluto. It talks about Pluto's
gravitation, saying:

"By measuring Pluto's pull on Charon as the satellite moves around the
planet, astronomers can estimate the mass of Pluto. (Current best
estimates are that Pluto's mass is about 3/1000th that of the Earth.) From
knowing the mass and the diameter, Pluto's average density (mass per unit
volume) can be calculated, giving us a due to what this remote world is
made of. On a scale where water has a density of 1.0 and the Earth about
5.5, Pluto comes in at about 2. This means it cannot be made just of ice,
but must also contain denser (rocky) material. Knowing Pluto's approximate
mass and diameter also allows us to estimate the strength of Pluto's
gravity at its surface -- it turns out to be only a percent or two of
Earth's! A 100-pound Earth student would weigh only a pound or two on
Pluto."

This paragraph came from
http://www.aspsky.org/education/tnl/10/10.html
and is (c) 1988 Astronomical Society of the Pacific

Is this what you needed to know?

Thanks for writing!
Kurtis Williams

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