Celestial body that orbits following an elliptical path around a star or stellar remnant.
4
votes
1answer
68 views
What if the Moon was 100x more massive: Binary planets?
I was reading a couple of Earth-Moon related questions (Mars just collided with Earth! A question of eccentricity, Could the earth have another moon?) and they got me thinking about planet-moon ...
5
votes
1answer
31 views
Correlation between speed, distance, mass, etc between a planet and a star (or moon and planet)?
While playing around with some little scripts, generating solar systems, I started to wonder about the correlation between the different objects. Up until now, distance, mass, size and speed are ...
1
vote
0answers
24 views
mutually tidally locked synchronous orbits
With synchronous orbiting natural satellites, such as Pluto and its satellite, Charon, I understand that that each are tidally locked to each other (Princeton's tidal locking reference).
My question ...
-3
votes
0answers
46 views
How to solve the mean anomaly of a planet? [closed]
I'm working on a project about celestial mechanics. The topic is 'the two bodies problem'.
I have to find the mean anomaly of a planet.
Using this equation, we should find it: $M(t) = M0 + n (t - ...
1
vote
1answer
43 views
Function for heating of a planet by its star
I'm looking for an algorithmic model which will gives rough estimate of the average temperature of a planet's atmosphere (good enough to say whether there will be liquid water anywhere, or if metals ...
-5
votes
1answer
53 views
What would happen if the moon was in perpetual opposition of the sun [closed]
What would happen if an artificial force made the moon to stay at a perpetual opposition from the sun?
Assume that the artificial force necessary is possible, and capable of making the moon stay at ...
3
votes
2answers
66 views
Saturn's polar versus equatorial gravity
Wikipedia's reference for Saturn's gravity gives $10.44 m/s^2$ at the equator, but this conflicts with Britannica, which gives $8.96 m/s^2$ at the equator and $12.14 m/s^2$ at the poles. All values ...
0
votes
2answers
88 views
Planet in which satellite(moon) and star(sun) appear together once a year
With a hypothetical system, where the moon would be always on the opposite side of the planet than the sun, in a way that the moon would only be visible at night on the planet.
I don't know if this ...
1
vote
2answers
71 views
Will a spinning object come to rest?
Will a sphere spinning on its own axis come to rest given enough time, provided no other forces act upon it?
I know that if you have two spinning spheres in the depths of space and orbiting each ...
11
votes
2answers
259 views
How large can planets or moons appear?
In many artistic impressions or movies there are pictures or scenes where the sky is filled with an enormous moon (as seen from a planet) or vice versa.
I wonder if there is an upper limit to the ...
5
votes
1answer
72 views
Do all known planets and moons have magnetic field?
In this Wikipedia article it is stated, that magnetic field of Earth is caused by currents in her core. The same origin is for Jupiter magnetic field.
For Moon (article) there is a magnetic field, ...
1
vote
1answer
72 views
What causes the collapse of a Magnetic Field?
It's theorized that Mars once had a magnetic field which collapsed at some point.
There's also lots of speculation that a similar process will eventually happen to Earth. More recently has been the ...
5
votes
1answer
68 views
What planets are visible to the naked eye from Mars?
Here on Earth we are blessed with being able to see some other planets, Mars & Venus etc, with the naked eye on a fairly regular basis thanks to the distance between the planets.
What about from ...
2
votes
1answer
73 views
Has martian sunset same spectra than this earthly bluish-violet sunset?
Has martian sunset same spectra than this earthly bluish-violet sunset?
What about sunset on Mercury?
8
votes
3answers
322 views
Is it possible that 5 planets can revolve around a single star in a single orbit?
I'm writing a novel and I'm quite confused if this system could be possible in the real universe. Is it possible that a system exist, where 5 identical planets which could be of same characteristics ...
5
votes
2answers
226 views
What is the largest sphere of liquid water that could exist in space held together under it's own gravity? [duplicate]
What is the largest theoretical sphere of liquid water that could exist in space held together under it's own gravity? I've always wondered if a planet the size of earth could exist as a single volume ...
1
vote
2answers
38 views
Solar Catastrophe [duplicate]
Consider all of sudden the sun vanishes. What would happen to planetary motion. Will it continue to move in elliptical path or move in a tangential to the orbit immediately after sun vanishes or move ...
0
votes
2answers
58 views
Saturn ring stabilization
The rings of Saturn are the most extensive planetary ring system of any planet in the Solar System.
I'm wondering, what power is primarily responsible for that stability?
© Public Image by NASA ...
0
votes
2answers
100 views
I want the Saturn's position in terms of Declination and Right Ascension?
I want the Saturn's position in terms of Declination and Right Ascension for a couple of month in the interval of 1 hour in a text file to do a simulation. Which site can provide me these data?
Or, ...
3
votes
2answers
137 views
Could a planet sized bubble of breatheable atmostphere exist?
I'm reading a book (Sun of Suns by Karl Schroeder) that the main location is a planet called Virga, which contains air, water, and floating chunks of rock, and has no or a very small amount of ...
2
votes
1answer
98 views
Motion of mercury [duplicate]
I studied that mercury motion around the sun slightly displace by a certain value in each year. But, this is not predicted by kepler until general theory of relativity. What does general theory does ...
7
votes
3answers
252 views
How do you explain Kepler's third law in general terms without complex math?
I understand the first law-elliptical orbits, and the second-equal area in same time, but I need help with the third one. Note that I am not in an AP course or taking calculus at the moment so simple ...
0
votes
0answers
25 views
Planets motion around the sun [duplicate]
Why planets of solar system move almost in the same plane?
0
votes
1answer
138 views
Where do planets get energy to revolve around sun?
We know that every planet in our solar system revolve's around the sun in a particular orbit. But were to they get the energy to revolve around the sun. And why do they not drop into the sun there is ...
4
votes
3answers
66 views
Length of day of a gas giant
How can the rotational speed, or the length of a day be determined or estimated in a planet which is composed entirely of non homogeneous fluids? There must be internal forces (pressure gradients, ...
3
votes
1answer
99 views
Link between Earth and Mars
I am trying to the calculate the link budget for link between a ground station on Earth (with a particular latitude and longitude) and a rover at a particular location on the surface of Mars, either ...
6
votes
1answer
94 views
How scientists could say that such meteorite comes from Mars
How could scientists affirm that a meteorite comes from Mars and not from another source ?
This is a probability or an absolute certainty ? How much percent ?
2
votes
2answers
57 views
Would a magnetic rod through Mars shield it from solar wind?
Would a magnetic rod going all the way through Mars shield it from solar wind?
2
votes
1answer
73 views
Magnetic field line length
If I had a magnetic bar in space that was 2cm wide and 2cm high and was one Earth diameter long and had the same magnetic strength as the Earth, would the distribution of field lines be the same ...
0
votes
1answer
46 views
Motion of binary planetary system perceptible?
If one were standing on a body that is part of a binary system such as Pluto/Charon, would the g-forces of the motion of the planet be perceptible by a human?
7
votes
3answers
178 views
Falling through the rotating Earth
Suppose you were standing on the rotating Earth (not necessarily Equator or the poles) and suddenly your body lost the ability to avoid effortlessly passing through solid rock.
Because the earth's ...
19
votes
6answers
2k views
Could there be a star orbiting around a planet?
I wonder if there ever could be a star (really small) which may orbit around a planet (really big)?
2
votes
2answers
87 views
Does Planet revolution time is always greater the more it's getting away from the center?
The entire question is in the title .
It's the case for the solar system but is it always the case ? Can a planet do a revolution faster than another that is closer to the center ?
As far as I ...
11
votes
1answer
147 views
Relationship between Mars and Earth rotation
Is it by pure random chance that Mars and the Earth have nearly the same day duration (Mars day is barely 40 minutes longer, which is just 3% difference), or there is some causal relationship between ...
3
votes
1answer
71 views
Does the Earth have a semi-solid body at its core because of lower pressure at the center of the Earth?
I have read that the Earth has a semi-solid iron body at its core, even though that object is surrounded by liquid magma.... I'm wondering if this is because of a pressure (and resulting temperature) ...
2
votes
1answer
209 views
Where to find the current positions and velocities of the planets?
I've written a program which simulates the motions of planets and other bodies. I'd like to run it on our own solar system, but to do so I need to know the current positions (preferably in ...
3
votes
3answers
197 views
Does Kepler's law only apply to planets?
Does Kepler's law only apply to planets? If so why doesn't it apply to other objects undergoing circular motion?
By Kepler's law I'm referring to $T^2 \propto r^3$
5
votes
1answer
84 views
Atmospheric Circulation
What is the simplest simulatable model giving our rotating earth its 3 circulation cells (Hadley, Ferrel, Polar)?
The model should also show 1 circulation cell if the earth's rotation were stopped (or ...
2
votes
1answer
145 views
How does one measure Earth's speed of revolution around the sun?
I know that there are several formulae that one can plug numbers into to arrive an estimate of Earth's speed around the sun (Kepler's third law for instance), but I'm wondering how these things are ...
4
votes
2answers
114 views
What is the mass distribution within the sun?
Jupiter is roughly 1/1000 the total mass of the sun. To get some idea of what effect Jupiter's gravity may have on the sun I'd like to know the approximate mass distribution of the sun. (i.e) the ...
6
votes
1answer
56 views
Is it possible to determine astronomically/astrophysically whether other planets have ever encountered polarity reversal?
We know of geomagnetic flip in Earth's history by studying geologic data. Given other planets in the system also possess a magnetic field leads to the assumption that such polarity reversal may not be ...
2
votes
1answer
129 views
Planetary Gravity and its effects
This is my first question on the Physics portion of Stack Exchange. I was hoping to get some light on the topic of gravity. I don't have much background knowledge of physics so I might as well start ...
2
votes
2answers
90 views
Can one predict mass distribution in a solar system given the mass of the star?
I'm trying to write a program to procedurally generate solar systems at a reasonably high level (I'm not interested in doing an n-body dust particle formation simulation).
Is there some sort of ...
5
votes
1answer
92 views
Convert latitude of lowest altitude to argument of perigee?
I am designing an orbit around Mercury. I know the values I want for the semi-major axis, eccentricity, inclination, and RAAN. I want the altitude of closest approach (periapse) to occur at ...
14
votes
2answers
286 views
How deep is the Great Red Spot?
The Great Red Spot (GRS) is a very persistent storm system that's easily visible through a telescope on the surface of Jupiter. But what is the three-dimensional structure of the GRS, and how deep ...
2
votes
3answers
935 views
Is it possible for the planets to align?
We've all heard the statement that on the 21st of December, the planets in the solar system will "align" from the point of view of the Earth. I assume this means that they would all be in the same ...
43
votes
5answers
2k views
Is there a small enough planet or asteroid you can orbit by jumping?
I just had this idea of orbiting a planet just by jumping and then flying upon it on its orbit kind of like superman. So,
Would it be theoretically possible or is there a chance of that small body to ...
1
vote
0answers
63 views
What is the critical mass of a planet to have an atmosphere like Earth's?
Small planets/orbits like Moon cannot have atmosphere because of their masses. They don't have enough gravity to hold an atmosphere. Then what is the critical mass that makes enough gravity to keep an ...
1
vote
1answer
220 views
Artificial planetary magnetic field
I wonder how difficult it is to create an artificial planetary magnetic field with generators? What power they would need?
The question is inspired by thinking about possible colonization of ...
3
votes
1answer
84 views
What is the maximum mass of planet HD 40307 g
Recently discovered planet HD 40307g around HD40307 Star system is claiming that its inside a habitual zone of a solar system. Besides It has water where life could be evolved.
I tried to calculate ...
