Questions tagged [natural-satellites]
Questions on celestial bodies that orbit planets.
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What kind of effects would two moons have on an earthlike planet?
On Earth our moon has several effects: it generates two high and two low tides a day; it slows down the spin of the planet and stabilizes its wobble, etc.
So, what possible effects could two moons, ...
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How close does a double-planet have to be to provide magnetic protection to a smaller body?
A spinoff of my previous question, regarding the Orbital Stability of a Double Planet System. Imagine two closely-orbiting bodies with a semi-major axis of 79,250 km. One of which is 2M🜨, with a ...
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Orbital Stability of a Double Planet System
I recently found an article claiming a double planet system needs to be at least .5 AU from its parent star to be stable for billions of years. It was specifically talking about two same-mass bodies, ...
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What are these bumps on Europa?
The surface of Europa is famous for all the criss-cross lines thought to be cracks in the ice above a water ocean that somehow re-freeze.
But in the photo below I also see a lot of raised "bumps&...
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How would ocean tides work on a tidally-locked planet?
Since the tidal bulge is always in the same place, how would that affect ocean tides? Would they change throughout an elliptical orbit, due to changing distance from the star? How exactly would they ...
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What is the brightness and size of Jupiter from the Galilean moons, the closest moon, and the farthest moon?
From the Moon, Earth would appear 4 times larger than the Moon seen from Earth, and the magnitude of a "full earth" is around -17.
However, Jupiter from the Galilean moons appear much larger ...
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If Ganymede had a thick, Earth-like atmosphere, would the surface be protected from Jupiter's intense radiation?
Obviously, this is a totally hypothetical, alternate version of Ganymede, since it would also need to have more mass and a stronger intrinsic magnetic field to hold onto a substantial atmosphere. But ...
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Why do Jupiter’s moons have so much water?
Why do Jupiter’s moons have so much water by mass? Did all the bodies in the solar system start out with this much water and the planets closer to the Sun simply lost it to space?
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Besides Luna, are there any models of how moons become spherical and round?
Question
Given the theorized exceptional formation of Luna, (Giant-impact Hyphothesis, Wikipedia), are there any similar animated models of how the other, much smaller, moons in our solar system ...
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What would be 1 hour equivalent on these moons of Jupiter and Saturn compared to earth? And their astrobiological implications
Considering the distance from and velocity of Sun, Saturn, Jupiter, thermal energy due to motion other than that adding/combining to velocity, and the individual mass and velocity of the particular ...
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Does a more massive main proto-body result in more massive satellites? More satellites?
Suppose that we have a forming protostar and an accompanying protoplanetary disk.
Does the mass of the protostar have any direct relation to the masses of resulting planets or amount of resulting ...
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If you were standing on a habitable moon of a gas giant, what would the planet look like during the day vs the night? [closed]
If you were standing on the proplanetary side of a habitable moon of a gas giant, and the moon had a thick enough atmosphere to make the sky blue, how would the gas giant look during the day? Would it ...
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Are there areas within Jupiter's magnetosphere without powerful radiation?
I know Jupiter has powerful radiation belts, but I'm wondering if there are places within the magnetosphere that are relatively calm. I'm asking about Jupiter (a gas giant we know) because I'm curious ...
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The moon rises at a different time each day, but that difference changes. Why?
Let's say the moon rose at 5pm yesterday and 5:30pm today. The difference is 30 minutes – but that difference changes from day to day and can be anywhere between twenty-some to seventy-some minutes. ...
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Orbital terminology for satellites relative to one another
Basic question, but I'm trying to describe a planetary system and coming up short on vocabulary. Do either of the following exist?:
A word for the closest pass between two satellites orbiting the
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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 ...
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Is the satellite of a small star in a binary solar system a moon or a planet?
What exaclty distinguishes a moon from a planet?
In a binary solar system that has a large star in the center and a smaller star - among some planets - orbiting that large star, and the smaller star ...
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Why don't we find planetoids at L4/L5?
We find small objects (asteroids and dust) in the stable Lagrange points (L4 and L5), but AFAIK no moons (by which I mean a mass that accreted into a body, as opposed to debris that has been captured ...
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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 ...
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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 ...
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Why doesn't Triton orbit over Neptune's equator?
In this answer, I wrote (on another account) why most moons orbit over their planet's equator.
Any rotating planet has an equatorial bulge that shifts its moons' orbits around its equator over long ...
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What are the most efficient ways to terraform Neptune's moon Triton? [closed]
I have seen on various sites and on youtube videos pertaining to the terraform of various planets and moons that are not habitable for now but they can be habitable in near future.
What are the ways ...
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Are satellites of trans-Neptunian objects classified as trans-Neptunian objects?
I can't seem to get a consistent answer regarding the question of whether or not satellites (moons) of trans-Neptunian objects are considered to be trans-Neptunian objects, given that they do not ...
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Jupiter's asteroid-like moons and planetary-systems around sub-brown dwarfs
Is it likely that any of Jupiter's small moons were formed in orbit around Jupiter or are they all captured asteroids? I thought of this question because I wondered whether the planetary-system of a ...
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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 ...
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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 ...
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Why is there a mountain inside the Herschel crater on Mimas?
If the Herschel crater was caused by an impact, why does it have a mountain at its very center, its peak up to 5 mi (8 km) in elevation?
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Has the rotation of Eris and Dysnomia been observed?
Since both Eris and Dysnomia have been captured on a single image, is it possible to shoot multiple images of them to see how they rotate around each other? Has this been attempted? We don't know much ...
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At what distance from the Sun can planetary moons exist?
Mercury and Venus are theorized to have no moons because they are so close to the sun.
Is there a theoretical distance in which moons tend to exist based on simulations?
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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 ...
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How massive does a moon have to be to have a stable magnetic field?
Is there a minimum mass or other minimum properties necessary for a body to have a strong, stable dynamo to create a magnetic field conducive for life?
For example, would it be possible for Titan to ...
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What is the longest natural bound orbit chain observed?
Define a bound orbit chain as a list of successively less massive bodies, each in a bound orbit with the bodies preceding it in the list.
Then an example of a bound orbit chain would be: <Sun, ...
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Is there a way to estimate or calculate the tidal range induced on a water-bearing planet?
Consider a system in which a central star is orbited by a planet with liquid water oceans, which is itself orbited by a moon.
Given the masses and distances between these three objects, is there some ...
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Moons within a Gas Giant
Assuming a gas giant is primarily gaseous past our visibility, is it possible that a moon traveling at a sufficient velocity would be able to exist within the atmosphere, or would terminal velocity ...
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Slow moving, flashing star-like object in the sky. What could it be? [closed]
The sky was particularly clear last night and I noticed an extremely bright star. I thought it was venus possibly but it was too low down and was flickering craziy. That meant that it couldn't be a ...
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Could an orphan/rogue planet have a moon?
Is there some reason why an orphan or rogue planet wouldn't have a moon? Let's say it started out in a normal system and then just got flung out by an unstable orbit.
Joe Smith
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Do moons experience periods of no sunlight when orbiting "behind" their planet?
I'm writing a story that takes place on the Saturn moon Iapetusand I was thinking that especially since Iapetus only has an inclination of about 17 degrees from the ecliptic, wouldn't there be a point ...
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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 ...
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How many Kuiper Belt objects have moons? How do we know this?
On 2012 in the New Horizons' The PI's Perspective Alan Stern wrote The Kuiper Belt at 20: Paradigm Changes in Our Knowledge of the Solar System (more also archived) which includes:
Most of the known ...
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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 (...
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Has any moon achieved "retrograde equatorial orbit"?
There are many moons which have low (almost negligible) inclination and can be considered to rotate at the planet's equatorial plane. For instance, Galilean moons have almost negligible inclination (&...
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Moons with curlicue paths around our Sun?
I naively believed that since our Moon orbits Earth, and since Earth orbits the Sun, the path our Moon might take around the Sun would be this type of epitrochoid curve:
I was surprised and delighted ...
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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 ...
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What is the naming convention for temporary moons?
Is there a naming convention for temporary moons? Or do they follow the naming conventions of other small bodies?
In the case of 2006 RH$_{120}$, 2015 HP$_{116}$, 2020 CD$_3$ and 2020 SO, the first ...
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What celestial body (inside the solar system) has the highest flattening ratio?
As a planet, Saturn has the highest flattening(ellipticity) which is 0.09796. So, it makes Saturn with the largest equatorial bulge as a planet and as such Saturn is the flattest planet.
However, I ...
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Why are the moons of Neptune sorted by diameter?
The five moons closest to Neptune are sorted by increasing size. Naiad < Thalassa < Despina < Galatea < Larissa. The trend continues with Proteus and Triton, only interrupted by Hippocamp, ...
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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?
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What caused these strange craters on Hyperion?
I was looking at pictures of the moons of Saturn and noticed that the craters on Hyperion have a strange shape, somewhat resembling sinkholes. They look a lot deeper than the impact craters on other ...
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How to calculate the frequency of a gas giant eclipsing the sun from a moon?
Say you have a moon around a gas giant which goes around a star. If the moon has an inclination of around 0° relative to the gas giant's orbit, the gas giant will eclipse the star every orbit of the ...
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What would a moon with a six-month orbital period look like from the earth?
This is a kind of follow-up question to "What orbital period would produce one New Moon (and one Full Moon) each year?"
Given the six-month orbital period that is needed to produce one New ...
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