All Questions
6
questions
5
votes
2
answers
289
views
Helium in Uranus atmosphere
I read that in 1986 Voyager 2 measured the composition of Uranus' atmosphere, which turned out to be composed of $85 \%$ hydrogen and $15 \%$ helium.
It's not clear to me how this relevant amount of ...
- 566
0
votes
1
answer
57
views
Gravity train in other planets?
A Gravity train (https://en.wikipedia.org/wiki/Gravity_train) goes through a tunnel inside a planet that connects point A with point B. On Earth, the train would not gain enough impulse to reach the ...
- 2,462
1
vote
0
answers
76
views
Is a planet hot inside because it is still hot from beginning, or continuously heated? [duplicate]
If a planet emerges from multiple colliding pieces, that causes its material heat up.
Later, an existing planet is continuously heated by radioactive decay, tidal forces and other effects.
But are ...
- 3,901
10
votes
3
answers
2k
views
How does one calculate where the "surface" of a gas-giant would be?
Okay, so Jupiter, Saturn, et. al are gas giants. I understand that they have large gassy atmospheres, which, due to the pressure would eventually become more and more dense as one approaches the ...
- 233
6
votes
3
answers
2k
views
What keeps a gas giant from falling in on itself?
There is not enough gravity at the center to start nuclear fusion, but it seems that there would be plenty enough to collapse the planet.
- 227
14
votes
6
answers
10k
views
Can low-gravity planets sustain a breathable atmosphere?
If astronauts could deliver a large quantity of breathable air to somewhere with lower gravity, such as Earth's moon, would the air form an atmosphere, or would it float away and disappear? Is there a ...
- 477