Questions tagged [natural-satellites]

Questions on celestial bodies that orbit planets.

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4
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2answers
278 views

Is it possible for a planet to have multiple moons in a nearly stationary orbit?

I have done a lot of searching online and while I have been able to find out that theoretically a moon could exist in a near-synchronous/stationary orbit, I am wondering if it is possible for multiple ...
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Would an analogue of the definition for planets also work for moons?

This is a follow up question to What exactly is a "moon"? The conclusions I draw from James K's answer is that the IAU should define what a moon is. They haven't done so yet, but they should. The ...
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What exactly is a "moon"?

Recently some new moons of Jupiter were discovered. However the moons are pretty damn small indeed - only a few kilometers wide. That makes me wonder if they should even be called moons in the first ...
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How did "oddball" Valetudo, Jupiter's new prograde moon, end up in a wider orbit?

I just saw this question and that got me to this NASA page which led me to this scientific article. “Our other discovery is a real oddball and has an orbit like no other known Jovian moon,” Sheppard ...
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1answer
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Did we discover 10 or 12 new moons of Jupiter?

I saw multiple news sites reporting that a team discovered 12 new Jupiter's moons: c|net - Twelve new Jupiter moons found, including one reckless one Discover - Jupiter’s Got Twelve New Moons — One ...
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1answer
156 views

Changes of the velocity of the Moon due to impacts from other objects?

Has the moon’s velocity changed since ‘shortly’ after it’s formation due to impacts? Wouldn't it be likely that a significant collision would have occurred over such a long period of time? It ...
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1answer
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Number of planets in a habitable zone with large moons [closed]

Excluding gas giants, roughly what percentage of planets in the habitable zones of their stars would have large moons like Earth does, as opposed to Mars and its small moons/captured asteroids?
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Say we were to bring Titan to Earth's orbit. How much would its atmospheric pressure change?

I've heard one of the reason why Titan has such a thick atmosphere is because of its really low temperature. So say that were were to magically bring Titan to the Same orbit as Earth, and the moon ...
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Can a planet's gravity rip out its moon's atmosphere?

We all know that solar flares can rip a planet's atmosphere if the magnetic field is weak.Solar flares travel at tremendous speed so when they hit the gas molecules of a atmosphere the molecules are ...
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1answer
820 views

Is there a significant temperature difference on the moon from apogee to perigee or vice-versa?

Do those few thousand kilometers of difference going around the earth significantly affect the amount of thermal energy the moon receives from the sun to warm up its surface? Also, are there more ...
5
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1answer
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How can a rotation period of a planet's satellite/moon be "chaotic" (like Hyperion around Saturn)?

According to wikipedia (see info below image) Hyperion's rotation period around Saturn is "chaotic". What does that mean? The period (in days/hours) is different every rotation without any law ...
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1answer
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New NEOs are found daily. Is there any evidence gravity is pulling them to a centralised location?

With all of the new NEOs (near-earth objects) are they being pulled in or are they interacting with each other?
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1answer
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How old are Janus and Epimetheus?

How old are Janus and Epimetheus, and are they believed to have formed out of a collision? (I think would explain their shared orbit). Not the age of their elements, which should be similar to the ...
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horseshoe orbits

I'm designing a moon system for a fictional setting, and recently came across the idea of horseshoe orbits. The gist of my question is how many objects can share a horseshoe orbital at a time? I ...
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1answer
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Do the number of moons a planet has affect the speed of the planet's rotation?

Would the tidal forces of multiple moons interacting upon a planet speed up or slow down the day length of the planet? I was thinking that maybe the planet's day length would be slowed down due to all ...
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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,...
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How can tidal heating lower Io's orbit?

This answer to the question Is Io a magic energy machine? suggests that the energy from the internal heating of Io due to tidal "squishing" as it moves cyclically closer and farther from Jupiter in ...
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2answers
415 views

Which moon has a scar as if it was torn in half and put back together?

When I was a kid I had several beautiful encyclopedias. In one of them there was a description of moon orbiting on of the gas giants that had huge ripples all along its surface. It said in the text ...
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1answer
181 views

What would theoretically be dissolved in the interior oceans of icy moons and planets?

I know we have some indication of "what's in the water" from the plumes of Enceladus, but would other places be the same. For instance, could the deep liquid water of Titan contain dissolved ...
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1answer
74 views

Is it possible for a moon to only be out at night?

(For the sake of this question, let's assume that all other factors are malleable.) Essentially creating a permanent lunar eclipse, could a moon orbit around a planet so slowly that it is always ...
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553 views

Eventual outcome of tidal acceleration and deceleration

So, I know the Moon experiences tidal acceleration from the Earth. And, from what I've read, if not for the fact that the sun would boil away the oceans and engulf both of them first, about 50 billion ...
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1answer
161 views

What is the official term for a relationship between a planet and its moons?

Sorry if this is a dumb question, I could not find anything naming this in my astronomy books, and Google searches only seemed to show me pages about astrology, [sarc] because naturally, human ...
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573 views

When will the next series of mutual eclipses of Jupiter's moons begin?

When I was young (I won't tell you when) I saw one of the four Galilean moons of Jupiter suddenly disappear while watching through a small refractor. It wasn't a coincidence, I'd seen the prediction ...
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Is it possible that a satellite creates a forever eclipse? [closed]

So, to add a bit of context, I’m doing the NaNoWriMo challenge, which consists of writing a novel of 50k words in one month. My whole idea is based around the following question: What would happen if ...
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1answer
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Could a binary system of two planets with oceans reflect each other?

If there were two earth-like planets in a binary system and one of them had landmasses, and the other one had oceans covering a significant amount of its surface, could you see the continents of the ...
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Why is Enceladus the only geologically active moon among its neighbours?

My understanding of why Enceladus is geologically active is that tidal forces from Saturn and - to a lesser extent - from the nearby larger moon Dione provide heat to the moon's interior, just like ...
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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 ...
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1answer
363 views

Could binary gas giants have ring and moon systems?

Would any moons/rings around either of the gas giants stay intact or get ripped apart by the tidal forces between the two giants? If any moons/rings are able to form around either of the giants, is ...
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1answer
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Io: Why so much sulfur?

Io is the only body in the Solar System whose crust is dominated by sulfur and its compounds. Carbon and nitrogen are also very common in the universe but we don't see them or their compounds in Io's ...
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Is there a timekeeping word for the orbit of a moon?

For a planet, we can colloquially refer to its period of rotation as a "day" and its period of revolution around its parent star as a "year." Some worlds have unique terms, such as Martian days being ...
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What of the following moon-situations would be better?

Okay, so imagine that there is an Earth-like planet, with the following conditions: It's further from it's sun than the Earth is from the Sun (not much, but enough for weather to be a little colder ...
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1answer
263 views

If I had a horseshoe orbit of two moons...

Consider an Earth-like planet, with two moons. I guess the two moons would have to be smaller than our own, for the system to be stable. Is that stable? I did some research, and apparently Janus and ...
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1answer
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Wondering about a horseshoe orbit

Since I'm not a physicist, I want to know how that system works. For instance, if there was a planet, very similar to the Earth, but with two moons, and the moons where in a horseshoe orbit, how does ...
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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,...
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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 ...
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What colours can rocky planets (or moons) have

I am currently working on a simple program to randomly generate and display rocky exoplanets (for a space based strategy game), but I am having some problems figuring out what colour the rocks of ...
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So is there nothing like satellite anymore?

I just read this article. I don't know how credible it is, since I couldn't find any link to the original paper. But it says that pluto will be considered a planet again, along with more than 100 ...
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Why do Uranus' and Pluto's moons orbit the equator? What makes a moons' inclination tilt with the rotational axis of their planet?

Uranus and Pluto have their axes of rotation almost 90 degrees towards the ecliptic. But why do their moons tilt the same way? Does it mean that their tilts were caused by passing near some external ...
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1answer
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Can the Moon provide momentum to an object in Earth's orbit? Gravity Assisted Boost [closed]

Can a satellite maintain an equatorial orbit around Earth near the Moon's orbit to receive partial gravitational boosts by gaining momentum as the satellite passes though the Moon's gravity well? I'...
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Which celestial object in the solar system has the fastest tangential velocity at its surface?

Consider all of the naturally-occurring objects in the solar system : in the reference frame of the object's center (ie, ignoring the orbital velocity around the sun or, in the case of satellites, ...
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1answer
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How do we know that a natural satellite cannot be a hollow object?

In their 1966 book, Intelligent Life in the Universe, Carl Sagan and Iosif Shklovsky state that "a natural satellite cannot be a hollow object." How do we know this is absolutely true?
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I think I saw a satellite disappear? or was it a star?

so i was gazing out of my balcony randomly and all of a sudden this red light moves across above, initial thought was that it was a star but it didn't blink, second thoughts was maybe a planet but it ...
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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 ...
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1answer
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How would a small TCO (temporarily captured orbiter) or other natural Earth satellite most likely be detected?

A sentence from the abstract of The population of natural Earth satellites states: At any given time there should be at least one NES of 1-meter diameter orbiting the Earth. The average temporarily-...
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1answer
207 views

How massive must a rocky body be to liquify adequately to eliminate internal mass concentrations that could disrupt natural satellite orbits?

Maybe a slightly weird question, and maybe more appropriate for some future geophysics SE, but I feel like this is what questions like Do moons have moons? are really driving at, and it just almost ...
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1answer
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If a captured moon has prograde, circular and equatorial orbit, can we know it is captured?

As we know, Triton has retrograde orbit , which is an stong evidence it is captured by Neptune. Suppose if a moon is captured, but results in prograde orbit, and the orbit becomes circular and lies on ...
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1answer
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More than 67 Jovian moons?

Wikipedia says that there are now 67 known moons of Jupiter. It got me wondering: is it really possible in our day and age that there are more, but we haven't observed them yet? On the other hand, ...
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601 views

Could this three moons system be stable?

In my fictional world I have selected all parameters to maximize the Hills Sphere of my planet. The planet has three times Earth's mass and it is located in 2 AU from its star that's 1.4 times more ...
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Is it possible for a moon to continuously have a side facing its star whilst orbiting a planet?

For example; is there any possibility for the moon to always have a side facing the Sun whilst orbiting Earth? And if so then what would the day cycle be like?
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If Venus had moon before and it fell back to Venus, why don't I see a unique, very big crater?

Does lack of a very big crater support the idea that Venus never had big moons before? If not, why can't I find a very big crater from the moon impact?