Questions tagged [natural-satellites]

Questions on celestial bodies that orbit planets.

22 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
4
votes
0answers
84 views

Are there any bodies in the solar system whose rotation is almost tidally locked or barely tidally locked?

The Moon's rotation is firmly tidally locked to the Earth and the Earth's rotation is firmly tidally unlocked with respect to the Moon. I gather that Mercury's rotation is tidally locked in a 3:2 ...
4
votes
0answers
138 views

Help identifying a very slow-moving object during meteor shower photography

I just wonder if anyone could shed any light on this puzzle. Two nights ago whilst I was out photographing the Lyrids meteor shower from the UK something else showed up on my images when I checked ...
4
votes
1answer
134 views

Is it possible to have a positive rational number of months (more than 1) in a year?

It is possible for a planet to have orbital resonance with a sun (e.g. Mercury has a 3:2 spin resonance with the sun). It is also possible for a moon to have orbital resonance with a planet (e.g. our ...
3
votes
0answers
46 views

How to distinguish primary hosts (stars) and orbiting satellites (planets) and tertiary bodies (moons) by their mass and trajectory?

Suppose one has run a gravitational simulation of N bodies (has the mass, vector positions, vector velocities, etc for each body), but knows nothing a priori about ...
3
votes
0answers
58 views

Which moons do have neutrospheres?

Or in other words: which moons do have ionospheres but not surface-bound ones? The space beneath an ionosphere is called a neutrosphere. I only know of Titan. I know that the Galilean moons and Triton ...
3
votes
0answers
35 views

Would magnetic reversals on Ganymede affect radiation levels at the surface?

Currently the intrinsic magnetic field of Ganymede is anti-aligned with respect to the Jovian magnetic field. If this situation changed to become aligned, either due to magnetic reversals of the ...
3
votes
0answers
84 views

What's the first written record of the moon being tidally locked to the earth?

I couldn't find references as to who first noticed (wrote down) that the moon was tidally locked to the Earth. This, to me, doesn't seem obvious from first glance, and looks like something only found ...
2
votes
0answers
40 views

Are there any moons of minor planets that orbit at high inclination to the plane of rotation of the parent body?

It occurred to me that one of the ringed asteroids or minor planets may answer this question about the alignment of planetary rings. However, it appears that the rings of Chariklo, Haumea and Chiron (...
2
votes
0answers
36 views

How many moons do we know are shepherds?

Shepherd moons are natural satellites near the edge of a planetary ring that have an influence on the shape and size of the ring due to their gravity. So it is possible for a satellite to be near the ...
2
votes
0answers
55 views

Keplerian Elements for the Moon and Earth around their Barycenter

So I'm looking to replicate the inner Solar System to a decent degree of accuracy. So far I've been utilizing the Keplerian Elements and Equations for the planets, as shown here. There is one issue ...
2
votes
0answers
78 views

Why was the diaeresis removed from Pasiphae?

The Gazetteer of Planetary Nomenclature notes that the spelling of Jupiter's moon Pasiphae was changed from Pasiphaë in July 2009, i.e. they removed the diaeresis. I've been unable to track down the ...
2
votes
0answers
54 views

Is the process responsible for Triton's nearly perfect circular orbit going to happen in my fictional world?

First of all, I'd like to point out that I'm a worldbuilder and I like my worlds to be as physically possible as... possible. I am in the process of building a world with a habitable moon orbiting ...
2
votes
0answers
47 views

Speed of Moonrise relative to fixed point on ground

Due to the curvature of the earth, and the way the moon interacts with the atmosphere (especially close to the horizon), is there a known function that describes the speed of the moon relative to its ...
2
votes
0answers
102 views

Moons of migrated giant planets: Icy, Rocky, or none at all?

My understanding is that gas and ice giants form outside the "snow line" of their protoplanetary disk, then sometimes through gravitational interactions they are able to migrate into the inner star ...
1
vote
0answers
23 views

Is there a reason Tethys and Dione are the only moons known to have trojans?

Trojans have been found at the L4 and L5 points of most planets. However Tethys and Dione, both moons of Saturn, are the only known moons in the Solar System to have trojans of their own. Is this just ...
1
vote
0answers
33 views

Why does Titan's (relatively) rapid migration away from Saturn cause the planet to wobble faster, and eventually (maybe) tip onto its side?

Over the past year and a half, multiple articles in the popular press have come out talking about how unexpectedly rapidly Titan is moving away from Saturn, and how this is causing Saturn to wobble ...
1
vote
0answers
25 views

How to determine how often a planet's center will be collinear with its moon's?

Expanding on the question: Let's say I have a planet orbiting some star (earth-like, sun-like, for the sake of example). If this planet has two moons, M1 with orbital period of 30 earth-days and M2 ...
1
vote
0answers
33 views

Can we see traces of exo-moon formation?

Our Moon was likely formed by the collision of a Mars-size object with the Earth soon after the planets first formed. Would traces of such an event be detectable by observing the protoplanetary disc ...
1
vote
0answers
191 views

How do I calculate the hour angle of a planet's moon from a point on that planet's surface?

I'm worldbuilding and I'm trying to construct a standing stone calendar that'll accurately denote where to look for my planet's moon at its four major phases from 53.8 degrees South. So, I need the h0,...
1
vote
0answers
173 views

Angles in Moon, Earth and Sun system

Consider the vector positions of the center of mass of Moon, Sun and Earth, $\vec{r}_{\rm M}$, $\vec{r}_{\rm S}$, $\vec{r}_{\rm E}$, respectively, in a given reference frame. Consider: the angle ...
0
votes
1answer
82 views

Can a terrestrial planet orbit an icy planet (or vice versa)?

I know that the composition of planets is dependant on the equilibrium temperature at its orbit - for example, if below a certain temperature, water and other volatiles become solid, allowing them to ...
0
votes
0answers
74 views

Could a moon of a mini-neptune around a red dwarf harbour life?

I am planning a game where on could control evolution on an alien world. I was thinking red dwarf as per here Habitable Planet around Red Dwarf To my understanding three questions arise: Tidal lock ...