All Questions
9
questions
1
vote
1
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Tidal forces in the early solar system
I'm reading a book called "Gravity from the ground up" by Bernard Schutz. I don't understand this section from Investigation 13.3 on page 159, which discusses the formation of the solar ...
- 11
0
votes
1
answer
634
views
Derivation of Roche Limit
In calculation of the Roche limit between the two celestial body, tidal force on small mass $u$, $F_t$ is expressed approximately as $$F_t=\frac{2GMur}{d^3}$$ While deriving $F_t$, what's the reason ...
- 39
3
votes
1
answer
99
views
If Saturn's rings cannot coalesce into a moon because of tidal forces, then how are shepherd moons able to exist?
From Wikipedia:
In celestial mechanics, the Roche limit, also called Roche radius, is the distance within which a celestial body, held together only by its own force of gravity, will disintegrate due ...
- 149
2
votes
1
answer
214
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Gravitational $n$-body problem with tidal forces
This year I'm working on modelling the gravitational $n$-body problem using Newton's law of gravity where I assume that for large enough distances, planetary bodies can be modelled as point masses. ...
user29305
2
votes
2
answers
320
views
How deep does a gravity well need to be to remove particles from a planetary body?
I almost considered asking this question on WorldBuilding, however I wanted the brute mathematics on the subject, so please excuse the theoretical nature of this question.
I understand the basic ...
- 123
2
votes
1
answer
247
views
Why does Moon always poses the same face towards Earth?
If both Earth and Moon are rotating as well as revolving around some focus, shouldn't they have drifted out of phase with each other long ago? So, why do we always see the same side always?
- 25
1
vote
2
answers
345
views
How can Rosetta spacecraft orbit an object with such a low mass?
Comet 67P Churyumov–Gerasimenko's mass is 11 orders of magnitude lower than Earth's. That means that the comet's gravity force is also weaker than Earth's in the same proportion. Provided that also ...
- 399
14
votes
5
answers
356
views
What is the most efficient way to travel between tidally locked binary planets?
Suppose that there are two planets of roughly the same volume and mass are orbiting each other. What would be the most efficient way to travel from one to the other? In other words, what kind of ...
- 361
4
votes
1
answer
3k
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What would it be like if we had a planet very close to us?
My desktop background rotates through a bunch of space and nature scenes, and this one came up.
What would be the effect on people walking around down here, if another earth was looming overhead ...
- 257