Questions tagged [orbit]
Questions regarding an object 'falling around' another object, due to a combination of gravity and momentum.
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1answer
48 views
How close would the sun have to get to a supermassive black hole to have Jupiter stripped and slingshot into interstellar space?
Please make whatever assumptions are needed. Assume sun approaches black hole on some sort of hyperbolic trajectory. Assume size of supermassive black hole is same as the one at center of our galaxy....
4
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1answer
232 views
Definition of Rotation versus Revolution
Let there be a planet for which the duration of a solar day is equal to a year around the sun such that:
...
4
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1answer
157 views
How feasible would it be to get to a planet orbiting directly opposite Earth?
Imagine that in addition to Earth, there was a second planet, say of one Earth mass, orbiting the sun - but on the opposite side of the Sun, and at the same orbital radius.
My question is - given ...
3
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2answers
62 views
How Does Earth Move In Relation To The Stars
In my simulation, I have stars scattered around Earth, all stars are the same distance from the center of the Earth and positioned based on their right ascension and declination like so:
I am ...
1
vote
2answers
52 views
Is it possible to affect Earth's orbit so that, say, aphelion happens sooner?
As part of its natural cycle, the sun is currently drifting away from the Earth, it's predicted to reach its farthest point by July 4th in 2020, at which point the distance between the Sun and Earth ...
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0answers
49 views
Is the angle of the Earth's orbit on the Galactic plane changing (towards 180 degrees)? [duplicate]
Currently the angle of Earth's orbit is aroun 60 degrees on the Galactic plane. But is this angle changing?
4
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1answer
103 views
Peculiar Amplitude of Earth's Orbit in Z Axis
I'm currently building an N-body simulator for my masters project and I'm using JPL's Horizons system to compare against.
I started with just a couple orbits and everything seemed to be working ...
2
votes
1answer
48 views
How to calculate the true length of day on a celestial body?
When I only know the sidereal rotation period, how do I determine the true length of day on a body?
We know the Earth's sidereal day doesn't have full 24 hrs unlike the true length of day. It's ...
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1answer
96 views
Path of Mercury and general relativity [duplicate]
I have read that many physicists challenge the theory of general relativity, and it has been proved many times that it is correct; my question is on Mercury's orbit. And we know that many of ...
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1answer
737 views
What is Charon's ascending node in reference to?
NASA's orbital elements given for Charon's orbit are given at https://ssd.jpl.nasa.gov/?sat_elem. The ascending node is defined as being "measured from the node of the reference plane on the ICRF ...
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0answers
60 views
Where and when will someone on Earth be standing with the floor parallel to the Ecliptic plane?
I have been trying to figure this out and I think the answer might be - once per day for anyone living on the Tropic of Cancer or Capricorn. Is that right? To be clear - I want to know where on Earth ...
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1answer
93 views
If you put all planets between earth and moon what would happen?
It's often discussed that you can fit all the planets in the space between the Earth and the Moon. But if they actually did teleport there instantly what would happen next?
Assuming their initial ...
2
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1answer
78 views
Can there be a three-moon system where only two are visible most of the time?
I am trying to build a moon system for a sci-fi work in collaboration with my boyfriend. He's the main writer and wants there to be three moons circling the planet in a way that most of the time, only ...
2
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1answer
79 views
What is the exact time of sun stay in each zodiac every year on sidereal year duration?
I tried to reverse engineer from astro-chart times at which sun stays in a zodiac.
Here is the list.
...
4
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0answers
76 views
Gravitational Slingshot
If a spacecraft slingshots around a planet P (with escape velocity V) at an angle $\theta$, I understand that the resulting velocity is $${ v }_{ 2 }=({ v }_{ 1 }+2u)\sqrt { 1-\frac { 4u{ v }_{ 1 }(1-...
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1answer
40 views
Does the orbits of stars in a binary system have a common focus, which is the center of mass of the stars?
I know that when a planet orbits a star (and assume the star is stationary because its mass is >> the mass of the planet), the orbit is an ellipse, and the star sits at one of the foci of the ellipse. ...
2
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0answers
55 views
Orbitally convenient Mars-to-Earth transit times?
Are there any peculiar solar system layouts that would result in highly efficient transits between Mars-to-Earth? I am aware of a Hohmann transfer orbit, but can other planets be used to "sling-shot" ...
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1answer
57 views
What's the difference between semi-major axis and apoapsis?
The semi-major axis is half of the diameter of the major axis of an ellipse by definition. So how does that make it any different from apoapsis, the furthest point an object is from a parent body in ...
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1answer
70 views
Can Kepler's 3rd Law be applied in higher dimensions to describe orbits (quadric surfaces)?
Motivation for asking:
The 2-D orbital path of a celestial body revolving around another celestial body due to the force of gravity can be described by a conic section; this is the curve formed by ...
4
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3answers
143 views
How long is the Sun closer to Earth then Mars is?
A recent question at Space.se has generated a few comments that are interesting.
But the answer to one particular comment to might address a lot of misconceptions.
I imagine the actual halfway ...
1
vote
1answer
92 views
Sun and moon's orbit in ecliptic coordinates using skyfield
I am new to using skyfield, is there any doc or help file that can show me on how to get the orbit of Sun and moon in ecliptic coordinate for a particular date and ...
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0answers
177 views
Orbits of planets in ecliptic coordinates
Is it possible to get the ecliptic coordinates of orbits of planets for a specific date and time? Does the ephemeris data of planets help in constructing that? Any help on this would be helpful. I ...
2
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1answer
136 views
Calculating object velocity at perihelion
I would like to calculate the velocity of an asteroid orbiting around a star (Sun) at the perihelion of its orbit. I know the excentricity of the ellipse and its semimajor axis.
I have found that the ...
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4answers
9k views
Is Earth's Surface “In orbit”?
I'm having trouble understanding relative angular/tangential speeds at increasing altitudes above Earth's surface. In particular, I find this comparison of tangential velocities on Wikipedia very ...
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2answers
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How to determine the orbital period of an asteroid using Kepler laws given its orbit's radius?
Given that the mean distance of an asteroid from the Sun is $450 \times 10^6$ km is it possible that the asteroid completes one rotation around the Sun in two years?
According to the third law of ...
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3answers
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Why are there so many binary systems?
Most star systems are binary, but why is that? Why would new stars form close to others, and not (relatively) evenly spread? And even if they are clustered close together, why are the majority binary? ...
3
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1answer
55 views
Beneficial astronomical uses of satellite constellations like Starlink?
Has any thought been given to software that would use predictable occultations by Earth-orbiting satellites to improve (rather than degrade) astronomical observations?
Potential challenges I could ...
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1answer
1k views
Troop of moving stars through a straight line [duplicate]
Last night,I and my brother suddenly saw that some(50-60) dots of light( exactly like stars) were moving through a straight line(from NW to SE) above us with same velocity and towards exactly same ...
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1answer
77 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 ...
9
votes
2answers
201 views
Could a star closely orbit a black hole long enough for the star to have lost 0.5B+ years to time dilation?
I was wondering how stable a close star-black hole system could plausibly be, and thus how much time a star could plausibly miss out on (from an outside observer's perspective) due to being in an ...
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0answers
66 views
Rocket Equation from Newton’s 3rd Law, Force of Gravitation, and dp/dt [closed]
I am using the derivative of momentum (dp/dt) with Newton’s 3rd Law with the gravitational force of Earth.
$$
F - F_{gravity} = \dfrac{\mathrm{d}p}{\mathrm{d}t} \\
F - \dfrac{G \, m_e \, m_r}{...
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0answers
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Find x,y,z velocity component of a star? [closed]
I am trying to find the initial x,y,z velocity components of the Epsilon Lyrae stars. How might I go about doing this? The radial velocities are available on Wikipedia, but I am not sure how to use ...
3
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1answer
79 views
Orbital speed is (vector) sum of tangential and normal speed?
Orbital speed definition in wiki does not state clearly - it is just tangential speed component or square root of squares of normal and tangential speed (full speed vector).
When we say that moon ...
4
votes
2answers
142 views
Can we calculate the orbit of exoplanets?
I'm not an astronomer, but the question came up and I'm interested if we are able (or how accurate we are able) to calculate the orbital parameters of an exoplanet. Since the transit method must yield ...
3
votes
2answers
44 views
Night-Day Cycles in S-Type Planetary Systems
I am a writer and space enthusiast. For a story I am currently writing I would like to have a planet which orbits a star which resembles the sun, which in turn orbits another star. In this situation ...
4
votes
1answer
114 views
Visitors that became satellites?
To anyone's knowledge, has there ever been an object that approached the earth and was captured into an orbit? Is it thought that there might be such objects simply too small to spot or just not ...
4
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1answer
116 views
Would two Earth-like planets on opposite sides of a Sol-like star at about 1 AU be a stable configuration?
Would two Earth-like planets on opposite sides of a Sol-like star at about 1 AU be a relatively stable configuration? I understand that there are tadpole-like orbits and the two planets may not stay ...
2
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1answer
86 views
By convention, when observing an exoplanet, is the observer's line of sight (on Earth) perpendicular to the plane of sky?
This is just a quick question. In this picture of the orbit of an exoplanet, is the observer's line of sight perpendicular to the plane of reference, which is in the +z direction on the diagram? In ...
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2answers
120 views
Are there any planets or objects orbiting in Goldilocks zone?
I was wondering whether there were any objects that orbit the "goldilocks zone" besides our home planet earth, and how the goldilocks zone of our solar system is defined.
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2answers
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Can a system of three stars exist?
Just like binary stars can a system of three stars mutually equidistant from each other?
What I mean is three stars at the vertices of a equilateral
If yes than what will be the orbit of a planet out ...
2
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1answer
92 views
How Long Will Earth's Year be When Our Sun Goes Red?
We live in a planet that orbits 93 million miles from a G-type main-sequence star, or "yellow dwarf". That is far enough for a revolution of 365 days. Such is the case of Kepler's Third Law of ...
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2answers
158 views
What is wrong with this measurement of the synodic period of Mercury?
I'm measuring the synodic period of Mercury using Stellarium. When measuring the synodic period one needs to choose a reference point to start the measurement, and I choose the point when Mercury is ...
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3answers
4k views
How do you call it when two celestial bodies come as close to each other as they will in their current orbits?
On Earth, we say Mars is in opposition when it is 180º from the Sun, which also marks the times when Mars and Earth come closest to each other.
Is there a specific name for such proximity events? For ...
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1answer
98 views
Why do transits of Earth across the Sun seen from Mars follow a pattern of occurring after 26, 79 then 100 years?
According to this answer transits of Earth across the disk of the Sun as seen from Mars:
The (Arthur C.) Clarke story is quite correct. Earth (and Moon) would transit the sun from the viewpoint of ...
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1answer
203 views
View of other planets from the Earth
There appears to be varying positions/spots of view of other planets from Earth, if I'm not wrong. Now, given that all planets are on the same plane, why do their positions change on the night sky for ...
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6answers
9k views
If the Moon were impacted by a suitably sized meteor, how long would it take to impact the Earth?
An answer to the question of How well would the Moon protect the Earth from a Meteor? mentions as a possibility that the Moon could get knocked into the Earth.
What is the smallest change to the ...
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0answers
63 views
When was it realised that most major moons orbit in the equatorial plane of their parent planets?
Inspired by the discussion of the moons of Uranus providing a clue to the planet's axis of rotation in this question, I'm wondering when it was realised that the major satellites are typically located ...
4
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4answers
194 views
Why does matter spiral into blackholes?
Narrators of astrophysics documentaries constantly state that matter spirals into black holes as if it were intuitive that this would happen because of gravity. But the moon isn't spiralling into the ...
0
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1answer
58 views
Lunar eclipse above the atmosphere
Would a lunar eclipse seen from low (or even high) Earth orbit look different to the naked eye than it does from the surface of the Earth?
The only image I could find taken from orbit was the photo ...
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1answer
81 views
Earth's perihelion vs winter solstice [duplicate]
I found that Earth's perihelion occurs roughly two weeks after winter solstice similar thing happens for summer solstice and aphelion. I understand what those terms mean but I don't understand the ...
