# Re: Jupiter's L1

From: Spike Jones (spike66@attglobal.net)
Date: Sat Dec 01 2001 - 22:38:22 MST

Damien Broderick wrote:

> At 07:41 PM 12/1/01 -0800, Spike wrote:
>
> >already knew the mass of the sun is about 2E30, so Ms/Mj = 1050
>
> Close; 1047.39

Now, do we *really* know the mass of the sun and Jupiter to
6 places? I'd give ya 4.

> >so square root of that is about 32, so the Sun/Jupiter L1 would
> >be 32 times closer to Jupiter than [to] the sun
>
> Cube root, I think. If so, circa 10.15 times => 0.092 of 5.2 AU = 0.48 AU,
> so I was close. *Is* it cube root? Damien Broderick

No. At L1, the gravity of Jupiter equals the gravity of the sun, so
plug it into the formula F=mMG/R^2. Everything cancels except
the mass of the planet and the R^2 in the denominator.

Ms/Rs^2 = Mj/Rj^2

Rj/Rs = (1047)^.5 = 32

Rs = Rj / 32

Rj + Rs = 5.2,

so Rs ~ 5

and Rj = .16

Damien I wouldnt steer ya wrong, bud, you're too nice a guy.
{8-] spike

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