Questions tagged [orbit]
Questions regarding an object 'falling around' another object, due to a combination of gravity and momentum.
642
questions
4
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1answer
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Where can I find a list of retrograde Milky Way stars?
I read in papers that the Milky Way contains some retrograde stars (retrograde to the Milky Way rotation). Does anybody know where I can find a list of them, possibly including data on their distance ...
3
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1answer
51 views
What is the longitude of the winter solstice for the various planets?
I am looking for data showing the longitude at which the various planets in the solar system reach their winter solstice. Where could I find this data?
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0answers
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What is the period of the 'cycle' of Earth's ecliptic variation, relative to the 'invariable plane'? 70,000 or 100,000 years?
The plane of Earth's path around the Sun, the ecliptic, is different from the average of the solar system's as a whole (the invariable plane) by about 1.57°....
Our path around the Sun, though, goes ...
5
votes
2answers
124 views
Estimating close approach between all asteroids themselves
I am currently writing a C++ program to show asteroids in 3D, and find close approaches or collisions. I got my orbital elements from JPL https://ssd.jpl.nasa.gov/sbdb_query.cgi. So far so good, with ...
18
votes
2answers
2k views
Is S2 still the fastest known star in the galaxy?
Wikipedia's entry for the star S2 says that it has
the fastest known ballistic orbit, reaching speeds exceeding 5,000
km/s (11,000,000 mph, or 1⁄60 the speed of light) and acceleration of
about 1.5 ...
0
votes
1answer
55 views
Orbit of Luhman 16?
I am studying some binary stars and brown dwarfs. Some orbits are known and easy to find, like Alpha Centauri. However, when I look for the orbital characteristics of Luhman 16 (AB), I only get the ...
11
votes
2answers
1k views
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, ...
7
votes
1answer
367 views
How to find the shape of an orbit
What is the minimum information I need to be able to draw the shape of an orbit of a body that orbits the sun? With this information how can I figure out the shape of its orbit?
2
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1answer
39 views
How can I find the width of an orbit knowing some values?
I need to find the width/x-radius of an orbit, which is ellipse shaped, knowing variables like the orbit's length(perihelion + aphelion in this case) and the eccentricity. I am not sure if this is ...
4
votes
3answers
704 views
Computing the rate of orbital decay
We know that the estimated time until a binary system merges is given by: $$\dfrac{5c^5r^4}{256G^3(m_1m_2)(m_1+m_2)}$$ But what is the formula to determine rate of decay, in some sort of distance unit,...
5
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2answers
183 views
What is the thickness of the Solar System disk?
What is the thickness in AU of the all planets' orbital plane height combined in the Solar System?
Excluding Pluto.
Looking for h
2
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1answer
60 views
Prograde to retrograde orbital path
Is there a planet or planetary moon flyby path that could send a solar prograde orbiting asteroid into a retrograde solar orbit?
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2answers
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What makes a star? [closed]
What are the properties of a star? How do astronomers classify the properties of stars?
3
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2answers
93 views
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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0answers
47 views
Visual binary star with circular apparent orbit
Does anyone know a good example of visual (or interferometric) binary star apparent orbit of which looks circular due to projection though in fact is markedly elliptical? I need that for teaching.
5
votes
1answer
92 views
Fate of a planet orbiting a Lagrange point behind a star?
Let's say there is a planet orbiting at L5 behind a star, which is in turn orbiting a more massive star, like so:
What is the ultimate fate of this planet? I'm predicting that it will spiral into the ...
17
votes
6answers
6k views
If the Sun disappeared, could some planets form a new orbital system?
If the sun were to suddenly disappear, the planets would continue to travel tangentially to their former orbits. (This I know from this answer to a somewhat related question here.)
In such a scenario, ...
3
votes
1answer
44 views
How long before Phobos reaches the Roche limit of Mars?
Phobos orbits really close to Mars, so close that one Phobos period is shorter than one sol. Due to tidal friction, it is also getting closer and closer to Mars. How much time will it take before ...
2
votes
1answer
104 views
Scholarly work on the gravitational disruption of a rocky planet by a close pass with another planet?
note: While the apparently abandoned question Effects of a rogue planet passing between the Earth and the Moon? (inspired by Thundarr the Barbarian) asks for speculation and was answered with it, this ...
3
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2answers
120 views
What are the Time Zones on Mercury?
I normally post on worldbuilding, but this question is merely about facts of a planets orbit and spin. I am trying to figure out how time periods work on Mercury to possibly make a worldbuilding guide ...
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0answers
77 views
Do the orbits of planets change? Where is the data for this?
Everything in the space is moving all the time.
Do the orbit of major Solar Systems planets, Mercury to Saturn change? Just like Moon's orbit around Earth changes.
How often, how small or big is the ...
9
votes
1answer
90 views
How can orbital resonance sometimes have a stabilising effect, whilst other times, it has a destabilising effect?
I have just started learning about orbital resonance. I understand how bodies in orbital resonance will line up according to the orbital ratio number, and there will be increased gravitational effects ...
2
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0answers
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Classical Mechanics : Interaction Sun Radiation Pressure - Gravitation
I have a theoretical problem that merges the effects of a gravitational field and the Sun radiation pressure. The problem goes as follows:
A spacecraft orbits the Sun in absence of any other body ...
1
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0answers
26 views
Sun's and planets' inclination to the Invariable plane
What are the inclinations of all major Solar system planets (Mercury to Pluto) to the invariable plane? Looking for accurate data calculated on them.
Also, What is the inclination of the Sun to the ...
2
votes
0answers
59 views
Moon's and nodes' inclination to the Invariable plane
Moon is inclined to the ecliptic 5.14 degrees. Earth's inclination to the invariable plane is 1.57869 degrees.
What is the Moon's, and node's inclination to the invariable plane?
Since the Moon has an ...
27
votes
6answers
9k views
The moon has just the right speed not to crash on the Earth or escape into space. What are the odds?
My understanding is that the moon was created a long time ago when Earth was hit by a big asteroid.
The debris then agglomerated into the Moon, which happens to be orbiting at the exact speed required ...
4
votes
2answers
771 views
Calculating the Angular Momentum of a planet
I want to calculate the Angular Momentum of any planet at any point on the orbit around the Sun.
Example: I want to calculate the Angular Momentum of Pluto today, on Jan 27, 2021 00:00:00 Hrs
Where ...
4
votes
1answer
93 views
Any known Triple Star Systems with this hierarchy?
I'm curious, are there any known STABLE triple systems in which a close inner binary pair is orbited by a more massive star, yet the total mass of the binary pair is greater than that single orbiting ...
0
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0answers
51 views
Why can't ESA/NASA build a handful of Gaia telescopes and launch them into different positions in space for better accuracy?
I've noticed that many stars in GAIA DR2 have highly uncertain distances. Why can't a space agency send multiple Gaia spacecraft into orbit around different places (One in L2 Earth, one in ...
5
votes
1answer
260 views
If two stars collide, what is the probability that they merge to form a single star?
After looking at What are the odds that the Sun hits another star? and answering it (crudely), now I'd like to ask the following:
What is the probability that if two stars collide, their cores merge ...
27
votes
3answers
3k views
What are the odds that the Sun hits another star?
The Sun moves around the Milky Way disk in the same direction as most of the other stars in our galaxy (prograde). But there are a number of older stars in the galactic halo that move in retrograde ...
5
votes
1answer
54 views
Does a star's rotation always match a planet's orbit?
For a planet orbiting a star, is it ever possible for a star to be rotating in the opposite way on it's own axis compared to the planet that is orbiting the star?
Or do gravitational forces mean the ...
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2answers
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Has the Earth's wobble around the Earth-Moon barycenter ever been observed by a spacecraft?
Pluto's motion around the Pluto-Charon barycenter has been imaged by the New Horizons spacecraft:
Has anything like this been imaged of Earth? Yes, the barycenter lies inside of Earth, but it is 3/...
3
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3answers
121 views
If an orbit is shifting due to orbital precession, is it still a Keplerian orbit?
I was thinking about orbits a few days ago, and realized that orbits shift/precess naturally. Given that a two-body problem with a star and a planet, if the planet has an eccentric orbit that ...
5
votes
2answers
95 views
Kepler's Law, focal points - Heliocentric or Barycentric?
It is known that all the mass in the Solar system moves around the Barycenter.
For the two focal points in Kepler's law; is the first focal point $F_1$ a Heliocenter? Or is it actually a Barycenter?
...
13
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4answers
3k views
Is it at all possible for the sun to revolve around as many barycenters as we have planets in our solar system?
Though it is understandable that the sun and the earth may be revolving around a barycenter, but, if so, not only the sun and Jupiter should also be revolving around some barycenter, the same should ...
6
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0answers
136 views
Are there any planetary ring system other than “Phoebe ring” not aligned to the equatorial plane?
Continuation of: Is it possible for planetary rings to be perpendicular (or near perpendicular) to the planet's orbit around the host star?
The answers discussed about Uranian ring system (how ...
2
votes
1answer
128 views
Will 1036 Ganymed's orbit be changed by its close encounter with Mars in 2176?
In 2176, the asteroid Ganymed will come as close as 0.02868 AU (4,290,000 km / 2,670,000 mi) from Mars. That's pretty close to Mars imho. Can Mars' gravity alter Ganymed's orbit significantly in 2176 ...
4
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3answers
248 views
How would the characteristics of a habitable planet change with stars of different spectral types?
The tidal forces a habitable planet experiences increase with decreasing spectral type. So a habitable planet orbiting a smaller, less massive, and cooler star would experience much stronger tidal ...
3
votes
2answers
368 views
Does the earth spiral around the sun's movement/motion path?
I have watched the following video (How Earth Moves by Vsauce) regarding how earth moves:
Here are some screenshots:
I have some questions:
Does the earth spiral ...
2
votes
1answer
71 views
Is Jupiter really shepherding the main belt, and Neptune the Kuiper belt?
By "dominating another object's orbit" my understanding is that the most massive body's gravity has so much influence that, when they come close, it makes the other body/bodies' orbits shift ...
8
votes
2answers
814 views
Where are Moon's Apogee and Perigee? Do they rotate too?
Where are Moon's Apogee and Perigee? Which one is inside, towards the Sun, between Sun and earth?
Do they rotate too just like the north, south node?
Does Moon always need to be on Apogee/Perigee ...
10
votes
1answer
534 views
Why does the angular size of the Moon change?
I know that the orbit of the moon is elliptical.
But I cannot understand this graph:
The number of 'bumps' in the graph is around 13~14 in a year, so I concluded that the each 'bump' indicates one ...
3
votes
1answer
68 views
What would the Earth's peri- and aphelion have to be in order to have the same seasons due to its orbit?
Imagine the Earth had no axial tilt but had seasons due to a very elliptical orbit. How elliptical would the Earth's orbit have to be in order to have about the same seasons as it has now (just with ...
3
votes
1answer
67 views
Problem with Tychonian model of geocentric universe?
Just like other proposed models of universe in history, Since Tycho's aren't being used, there MUST be any flaws in compare with widely agreed today understanding
Is there any detailed reference ...
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4answers
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Does a parabolic trajectory really exist in nature?
It seems it is very difficult to have e=1 perfectly in nature. The final state (being captured or running away) of a celestial body with a parabolic trajectory,
is determined by minor perturbation?
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2answers
101 views
North node, South node correct understanding
What is the correct concept of the North node and South node? There is some conflicting information on the internet.
Which one of these two is correct?
1. Sourced from some Astrology material - How ...
5
votes
1answer
145 views
Is a three body gravitating system doomed to collapse?
Suppose we have two gravitating bodies, which are rotating around each other. They are bodies and are affected by deformation caused by tidal forces. Moving tidal waves suck energy from the axial ...
20
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3answers
4k views
Does anything orbit the Sun faster than Mercury?
Mercury's orbital period around the Sun is about 88 days. Comets and other things have gotten closer to the Sun than Mercury does. But has there ever been an asteroid or some other body discovered ...
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vote
1answer
73 views
What would be the year length of a habitable planet of 40 Eridani A?
The planet Vulcan, in Star Trek, is one of the most famous fictional planets.
The length of a Vulcan year comes up in my answer at:
How old was Spock in Star Trek while he was serving on the ...
