All Questions
11
questions
2
votes
1
answer
69
views
On the tidal heating of a moon. What is the second Love number?
Years ago it was asked here how to calculate the tidal heating of a moon orbiting another body with a simple equation. The answer is very detailed. They explain the equation, its shortcomings, the ...
2
votes
1
answer
290
views
What is the rate of change of the Moon's eccentricity?
So I know the Moon's current average eccentricity is ϵ≈0.039±0.006, but was this always the case? Was it ever increasing or decreasing, and if so is it known what the current rate of change is for it? ...
- 161
1
vote
1
answer
150
views
Will a body as big as the moon collapse inwards if it was partially hollow?
Take a hypothetical scenario where the moon is hollow upto R=R/2
So will the moon collapse inwards as there is nothing to balance the gravitational force from outside?
- 21
0
votes
1
answer
65
views
Is it physically possible the existence of moons or planets where objects float permanently above the surface?
I found the following exercise while studying gravitation:
A small moon of mass $m$ and radius orbits a planet of mass M, keeping the same face towards the planet. Show that, if the moon approaches ...
- 493
2
votes
2
answers
240
views
Tidal forces between Moon and Earth
I started studying about gravitation recently and I came across the fact that when finding the gravitational force between the earth and some point mass in space, we can consider the mass of the earth ...
- 167
1
vote
0
answers
22
views
How severe would the consequences be if the earth's moon were wrenched from orbit?
The old TV series Space 1999 from the early 1970s seems to have resurfaced on Youtube reminding me of something I watched as a child.
It is one of those obviously ridiculous SciFi series (from the ...
- 2,572
-1
votes
1
answer
74
views
Imagine the Moon takes 5000 Years to fall on Earth, what power does it bring? Is the flux of power higher than the one received by the Sun?
Imagine the Moon takes 5000 Years to fall on Earth, what power does it bring? Is the flux of power higher than the one received by the Sun?
I would like to know which formula I can use, do I need to ...
- 1
0
votes
3
answers
1k
views
Why the Moon does not change its orbit from Earth to an another planet?
I know that Earths gravity pulls down the Moon towards the Earths center and Moon is falling on Earth, but because of its change in velocity it never fall on Earth but orbits around Earth.
Now I don'...
- 135
0
votes
2
answers
377
views
Gravity underground on the moon?
They say that gravity Decreases as we dig into the earth. But I also read that gravity increases for the first approx. 2000km of distance underground. Using this rational, could we dig about 200 to ...
10
votes
5
answers
37k
views
Why does the Moon not revolve around the Sun directly?
The sun pulls on the moon with a force that is more than twice the magnitude of the force with which the earth attracts the moon. Why, then, doesn’t the sun take the moon away from the earth?
- 219
33
votes
3
answers
12k
views
Why does the Moon face Earth with the same side?
I know that the rotation period of the moon equals its revolution period. It's just so astonishing that these 2 values have such a small difference. I mean, what is the probability of these 2 values ...
- 495