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max8166
2007-Jul-27, 03:15 PM
In what order do the planets of the solar system have a gravitational effect on the Sun?
I know that Jupiter is the most massive planet but it is a lot further away from the Sun than Mercury which is a lot less massive.

I think you could calculate this by multiplying the mass of the planet by the inverse square of the distance. Is that right?

Tobin Dax
2007-Jul-27, 03:26 PM
Yep. The force due to gravity is proportional to M/R2. When comparing planets like you want, those are all need since everything else cancels out of the ratios.

hhEb09'1
2007-Jul-27, 03:33 PM
Definitely Jupiter, still in first place, then Saturn.

antoniseb
2007-Jul-27, 03:42 PM
I'm not sure what you are asking.
Do you want to know the order that the planets have in terms of tidal (differential gravitation) effect on the Sun, or just simply attractive force felt, or which planet has the biggest impact moving the Sun from the barycenter of the Solar System? These would be three different answers.

hhEb09'1
2007-Jul-27, 03:51 PM
I'm not sure what you are asking.
Do you want to know the order that the planets have in terms of tidal (differential gravitation) effect on the Sun, or just simply attractive force felt, or which planet has the biggest impact moving the Sun from the barycenter of the Solar System? These would be three different answers.The OP makes it clear, to me, that they are asking about the second case ("gravitational effect", "multiplying the mass of the planet by the inverse square of the distance"). The first case would be inverse cube, and the third case just inverse, right?

max8166
2007-Jul-27, 03:55 PM
I'm not sure what you are asking.
Do you want to know the order that the planets have in terms of tidal (differential gravitation) effect on the Sun, or just simply attractive force felt, or which planet has the biggest impact moving the Sun from the barycenter of the Solar System? These would be three different answers.

Actually I would have thought these effects were all similar and proportional (if not why not?)

max8166
2007-Jul-27, 04:00 PM
1. Jupiter 318 earth masses 5.2 au = 318/27.04 = 11.76
2. Mercury 0.55 earth mass 0.39au = 0.55/0.152 = 2.56
3. Venus 0.82 earth mass 0.7233au = 0.82/0.523 =1.58
4. Saturn 95.2 earth masses 9.54au = 95.2/91 = 1.046
5. Earth 1 earth mass 1 au = 1/1 = 1
6. Mars 0.11 earth mass 1.52 au = 0.11/2.31 = 0.05
7. Uranus 14.6 earth masses 19.2 au = 14.6/368.64 = 0.04
8. Neptune 17.2 earth masses 30 au = 17.2/900 = 0.02


So does the effect of Saturn roughly equal the effect of the Earth on the Sun? (gravitationally)

Lord Jubjub
2007-Jul-27, 10:29 PM
I thought the tidal effect was the difference between pull of the near side of the target minus the pull of the far side?

antoniseb
2007-Jul-27, 11:15 PM
Actually I would have thought these effects were all similar and proportional (if not why not?)

1. Differential gravitation goes inversely as the cube of the distance

2. Gravitational acceleration (Newtonian model) goes inversely as the square of the distance.

3. Barycenter shift goes as linearly with distance (thus something 1/100 the mass of Jupiter at 500 AU is equal to Jupiter in this effect (but much slower).

hhEb09'1
2007-Jul-28, 02:04 AM
3. Barycenter shift goes as linearly with distance.Oops. Yes, that's what I meant. :)

mugaliens
2007-Jul-30, 02:40 AM
So does the effect of Saturn roughly equal the effect of the Earth on the Sun? (gravitationally)

Yep.