Celestial body that orbits following an elliptical path around a star or stellar remnant.
0
votes
2answers
45 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
57 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
204 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
66 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
55 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
49 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 ...
1
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1answer
58 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?
-1
votes
0answers
102 views
When can a body of water glow in space?
How would superionic water be formed at the core of a giant water planet? The publication
Giant planets may host superionic water, E. Marris, Nature News, 22 March 2005,
states that water in ...
8
votes
3answers
312 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
214 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
55 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
84 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
132 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
83 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
228 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
123 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
65 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
96 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
0answers
85 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
53 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
72 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
44 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?
6
votes
3answers
171 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
85 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
138 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
70 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
188 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
187 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 $T^2 \propto r^3$
4
votes
0answers
63 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
126 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
115 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
87 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
85 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
276 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
716 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 ...
42
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
61 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
185 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
83 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 ...
4
votes
0answers
87 views
Hemispheric dichotomy of Mars and unstable spin axis
Is the following explanation plausible? Can you spot any flaws?
Mars doesn't have a large moon to stabilise its axis of rotation. At some point early in its formation its axis might have been ...
4
votes
1answer
132 views
What day/night cycles, climate and seasons would experience Alpha Centauri Bb inhabitants?
Alpha Centauri Bb is an exoplanet orbiting Alpha Centauri B. It is asserted that given the close distance to the star the planet should be tidally locked.
The orbiting period of the planet is about ...
2
votes
1answer
339 views
Why are the orbits of the planets in our solar system along the same basic plane? [duplicate]
Possible Duplicate:
Why are our planets in the solar system all on the same disc/plane/layer?
After watching this video I realized that the orbits of the planets in our solar system ...
1
vote
1answer
727 views
What is the relationship between mass, speed and distance of a planet orbiting the sun?
After reading this fascinating story about a new exoplanet, I was wondering about how mass, speed and distance determine a circular orbit of a planet around a star.
Given the mass of the sun and ...
0
votes
0answers
48 views
Martian ground exchange heat pump
According to the wikipedia article Geothermal heat pump, "Depending on latitude, the temperature beneath the upper 6 metres of Earth's surface maintains a nearly constant temperature between 10 and 16 ...
4
votes
2answers
294 views
What does the phrase “limb of the earth” or “atmospheric limb” mean?
What does the term limb of the earth (see this question, for example) or atmospheric limb mean? The phrase strikes me as very odd, since earth is nearly spherical. Do other planets with atmospheres ...
