Questions tagged [planetary-systems]
Questions regarding the non-stellar objects gravitationally bound to a star or star system.
35
questions
1
vote
1
answer
53
views
Is the magnetic permeability (mu_0) necessary in the expression for planetary magnetic field?
To numerically analyse the Lorentz effect due to the magnetic field, say, radial component on a charge particles which of the expression would be correct, $\{ B_r = \frac{2R}{r^3} g_1^0 \cos(\theta) \}...
- 145
4
votes
2
answers
950
views
What's the simplest evidence for Kepler's first law?
What is the simplest explanation that provides enough evidence for the first Kepler law?
i.e. that planets around the Sun travel on ellipses with the Sun at one of the two foci.
Are the three Kepler ...
- 73
2
votes
1
answer
66
views
The path of a particle in planet's magnetic field doesn't not seem to change with the charge of the particle. Can someone please check what is wrong?
I am trying to plot the path of a charged particle in a planet's magnetic field. For positive and negative charge (β=charge/mass) different solutions/paths are expected. But,I got the same solution (...
- 145
2
votes
1
answer
64
views
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 ...
- 171
2
votes
1
answer
164
views
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, ...
- 171
7
votes
1
answer
146
views
Do planets affect their stars beyond causing them to wobble?
Are there any situations in which the existence of a planet measurably affects its star, aside from orbital wobble? I am curious about possible ongoing affects, not stuff that happened during stellar ...
- 751
4
votes
2
answers
883
views
Radio signals between Mercury and the Moon during an eclipse
This is a hypothetical question. Thank you for your time and efforts.
A signal is sent from a transmitter on Mercury's surface while it is at its greatest western or eastern elongation. The signal is ...
- 171
2
votes
0
answers
11
views
What are different forces acting on a planet which may be related to axial tilts?
In our solar system, we see that the axis of rotation of planets is tilted forex. The axial tilt of Venus is near 179 degrees. Venus, Uranus, and Pluto have large values of axial tilt(more than 90 ...
- 949
7
votes
2
answers
115
views
Is the Michael H. Hart range for the Habitable Zone (Goldlocks Zone) still used?
We're having an argument on another site about the Hart definition of the CHZ. In 1979, Hart provided a very conservative estimate of habitable zone: 0.958 - 1.004 AU. This was used to substantiate ...
- 233
2
votes
1
answer
58
views
Meteroids escaping the system
So the sun or any star has a certain gravitational pull. Technically the gravity extends infinitely only it will just become really small. If there is a meteroid around a star how do I calculate when ...
23
votes
10
answers
7k
views
Is the closest planet to another planet always the innermost planet?
In our Solar system Mercury is not only the closest planet to Earth on average but also, for the same reason, the closest planet on average to all other planets (Jupiter, Neptune, etc...).
Does that ...
- 331
9
votes
1
answer
210
views
What's the expected distribution of planet masses in a given system?
Given that the mass of a planet at a given orbital distance r is dependent on the protoplanetary material in the neighborhood of r at the time of formation (assuming no planetary migration), what ...
2
votes
1
answer
115
views
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 ...
- 920
8
votes
7
answers
3k
views
Could a planetary system have a planet in its center? [duplicate]
Is it known, or at least known that it is feasible, to have a planetary system with a planet in its center, and not a star? Would it be too surprising to find a planet as barycenter and some stars as ...
- 217
3
votes
1
answer
51
views
I have a question about the wording in a paper about a planetary system and comets
I was reading a paper. This is the paper:
https://arxiv.org/abs/2006.01711 (https://ui.adsabs.harvard.edu/abs/2020MNRAS.496.4979D/abstract
In the method section in the second paragraph there is a bit ...
6
votes
1
answer
168
views
Would it be possible to discover an asteroid belt around another star?
With existing or planned technology (e.g. the ELT or the JWST), would it be possible to infer the presence of a ring of asteroids similar to our own asteroid belt? Or would any signal be drowned out ...
- 17.4k
4
votes
2
answers
1k
views
What are the correct positions or alignment of planets in relation to each other and the Sun, is it vertical center, baseline or completely random
From a lot a illustrations and videos, the planets seem to align in vertical center to each other like this:
Is this really true? I like to imagine that the planets are actually in weird alignment to ...
- 343
5
votes
1
answer
115
views
Can the order of planets change in a young planetary system?
The Nice model and the Grand Tack model both show that the distance between a planet and its host star can change greatly over time. Is it possible in either of these models for the order of planets ...
- 17.4k
4
votes
3
answers
441
views
Impact on the rest of the solar system if Mercury or Venus were disassembled?
I've watched a few theoretical videos about Dyson spheres where they mention that the most practical way to do that would be to disassemble a planet - preferably one already close to the sun - Mercury ...
- 175
1
vote
1
answer
141
views
Is a Procyon - brown dwarf - Jupiter - superearth - Mars - Pluto system theoretically possible? [closed]
I once conducted a thought experiment and with some amateurish calculations based around Hill sphere and Roche limit came up with semi-major axis distances like this:
...
- 159
1
vote
0
answers
107
views
Binary planet orbital distance
From reading various sources online, I see that some people talk about binary planets in very tight orbits (around 1 or 2 planet radii). I am wondering if it is possible for a binary planet (Double ...
- 305
4
votes
2
answers
300
views
How many exoplanets have been found around binary stars?
This XKCD whatif talks about circumbinary and [the other kind of] exoplanets. How many such exoplanets have actually been discovered?
I tried to look it up at exoplanets.org, but didn't find a column ...
- 17.4k
1
vote
1
answer
383
views
How to find the Orbital Period of two Binary Planets around a Single Star?
This is kind of a weird one. Bare with me! :)
Background: (Skip to the math below if you just want to answer questions)
In my favorite game, Elite: Dangerous, I "own", or occupy I guess, a system ...
- 13
1
vote
1
answer
89
views
tidaly locked celestial body in three planet system
If a Planet have 2 Moons (so suppose system of 3 bodies) and we say "One Moon is tidally locked to Planet" how can we say that it is tidally locked when Baricenter of 3 bodies has its trajectory?
- 113
5
votes
1
answer
207
views
Is there any theoretical or empirical research about planetary systems with a black hole in their center?
I assume such a system would be hard to detect due to a lack of radiation, at least if the vicinity of the black hole does not contain a lot of mass which falls into it over time, thus creating (a lot ...
5
votes
1
answer
202
views
Is there a preference for orbital planes of planetary systems to be aligned with the galactic disk?
I'm not sure for how many planetary systems we have a fairly good idea of the inclination and "argument of periapsis" of the orbital plane. I'm assuming there are a number of them that we can estimate ...
- 2,902
4
votes
1
answer
2k
views
Average number and type of planets orbiting given star types
I don't need "exact" numbers, but I'm trying to create an auto-generator for a stellar map to crate stars that are "somewhat" accurate.
I'm looking for numbers on the average number and type of ...
- 397
2
votes
1
answer
964
views
What are the natural life sustaining resources available in the Jovian moon system?
Hard science fiction writing question. Premise: what natural resources are present in the Jovian system that would be necessary and desireable to an autonomous, self-sustaining human community? ...
- 23
1
vote
1
answer
100
views
Resources on planetary stability
I am a fifth (and last) year undergraduate student in Physics with good level of Mathematics formation and basic Astrophysics formation. I recently read some theories about Solar System formation and ...
- 408
2
votes
3
answers
175
views
How do we know that other planetary systems aren't composed of antimatter? [duplicate]
How do we know that other planetary systems aren't composed of antimatter? If they never touch matter, then they don't annihilate. All their observable physics (spectra) are the same as matter, right?
3
votes
2
answers
1k
views
Are there equations to simulate creation of a solar system?
I've been wanting to create a simulator to run tests based on properties of a star to find patterns in how planets form. Are there any already made equations for any of these countless relationships? ...
- 125
0
votes
1
answer
283
views
Venus started with retrograde rotation? [duplicate]
I have heard that when our solar system formed that all planets except Venus were revolving around the sun in the same direction because of the normal rotation of their axes. Venus was rotating and ...
- 269
1
vote
2
answers
162
views
any unique phenomenon when the cores of two planets are aligned with their star's core?
Imagine a line passing through the cores of two planets (in the same planetary system) and their star. Have we ever witnessed this - either with both planets on the same side of the star or on ...
- 119
3
votes
1
answer
303
views
Is the argument of perihelion random?
I am currently designing star and planet systems in the RPG framework GURPS. This game system has a very elaborate set of rules to set up a star system, complete with planets and the like. However, ...
- 133
15
votes
4
answers
543
views
When will we be able to detect Earth-sized exoplanets?
I have heard that the only planets able to be seen outside the Solar system are Jovian-sized planets with the occasional detection of planets three times the Earth's size. But, as far as I know, we ...
- 2,021