Questions on celestial bodies that orbit planets.
Questions tagged [natural-satellites]
229 questions
41
votes
3 answers
Do moons have moons?
Have we discovered any natural satellites of natural satellites of planets or dwarf planets? Even very small, or relatively short-lived - e.g. ringlets around Saturn's moons, some meteorites orbiting Jupiter moons, or something to orbit Charon? Or…
SF.
- 6,259
- 2
- 26
- 53
9
votes
2 answers
Natural satellites for Mercury
Would it be possible that Mercury had a natural satellite but the gravitational pull from the Sun became so overwhelming from it growing over the years that it just sucked in Mercury's moon?
user25024
- 91
- 1
7
votes
3 answers
Are moons geologically active?
Are there natural satellites in the Solar System that are geologically active? This includes volcanism, existence and motion of tectonic plates, et cetera.
Is it a common or a rather rare feature among such bodies?
Zoltán Schmidt
- 2,278
- 2
- 17
- 29
6
votes
1 answer
Theoretical limits for natural satellites having natural satellites
Is there an inherent instability or limit that prevents natural satellites like the moons of Jupiter from having their own natural satellites?
I looked at other questions such as do moons have moons but they focus on discovery rather than…
Erik
- 161
- 4
4
votes
1 answer
Could the Moon naturally capture a large asteroid and keep it as a subsatellite? For how long?
(Edited at James K's recommendation to stay on-topic for this SE.)
From my reading on this SE and from Googling I've gotten conflicting reports on the viability of subsatellites this close to the Sun, but a naive application of the Hill Sphere…
Lielac
- 43
- 5
2
votes
1 answer
Why does an irregular moon point its longest axis towards its parent planet?
I'm reading the book Ice Worlds of the Solar System. Page 62, it states that an irregular moon should point its longest axis towards its planet. Why is this the more stable configuration?
usernumber
- 17,492
- 3
- 54
- 133
2
votes
0 answers
New temporary moon of earth
A new temporary moon named 2020 cd3 has been discovered. How can we determine that this is temporary and why does it have such an orbit which is such irregular in shape ?
Salazar
- 317
- 2
- 7
2
votes
0 answers
What is the precise definition of a moon?
With the recent discovery of Saturn's 20 new moons (elevating its position on the rank of planets with the greatest amount of moons, surpassing Jupiter), it makes me wonder: what are the requirements a celestial body has to meet to be considered a…
Jove
- 21
- 2
2
votes
2 answers
Could a moon orbit two planets at once?
Let's say you had a binary planet system of two earth-sized worlds with about the same mass. Could a stable moon orbit around the barycenter of both planets? If so, is there a limit to the mass of such a moon? Would it have to orbit in a Lagrangian…
Gliese
- 831
- 6
- 10
0
votes
0 answers
Is there a minimum size for a moon?
Is there a minimum size for a moon? Is there a lower bound below which it's simply considered as being a rock? Or could you can every piece of rock and Ice in Saturns rings as an individual moon.
blademan9999
- 977
- 2
- 21