Questions tagged [orbit]

Questions regarding an object 'falling around' another object, due to a combination of gravity and momentum.

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2 votes
2 answers
110 views

How to find the numerical positions of objects in the sky?

How do star locator applications such as SkyGuide, SkySafari and Stellarium get the current and future positions of moons, planets, stars and artificial satellites in the sky? Is there a public ...
1 vote
0 answers
27 views

Does Trappist-1 have a Periodic Configuration? [duplicate]

Trappist-1's planetary system is notable for having 7 planets in a resonance chain. I would think, since all the planets are in resonance, the system would have a repeating configuration that could be ...
30 votes
3 answers
5k 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 ...
2 votes
0 answers
37 views

Satellite angular velocity at an angle

Suppose I am observing a satellite that is not at my zenith. I know the altitude(α) and azimuth(γ) of my telescope and I was able to get a relative angular velocity of the satellite. Based on this ...
0 votes
0 answers
85 views

How do I calculate the positions of an artificial satellite for a decade?

We are trying to solve what I think should be a simple question: suppose there is a satellite that is launched into a certain orbit, where will it be as a function of time? Let's say we know that it ...
3 votes
2 answers
203 views

Is there a general term for epicycles, deferents, and eccentrics in Ptolemaic astronomy?

According to Ptolemy's (c. 150 CE) account of the motions of planets, planets moved in circular paths ("epicycles") around center points that in turn moved around the center of the earth along a path ...
2 votes
1 answer
148 views

What should be the "poles" for irregular shaped bodies?

Continuation of: What is the definition of a "pole" of a celestial body? uhoh's answer says that distinct bodies should have a center of mass. If the body is spherical, then the COM will be ...
1 vote
0 answers
53 views

Are short-period comets more stable (in their orbits) than long-period ones?

Why the sharp distinction between short-period (P) comets of less-than-200-year orbits and those (C) with even slightly longer ones? To explore the possibility that it has to do with stability, I will ...
2 votes
2 answers
928 views

Why does the sun rise north of east between the vernal and autumnal equinox?

Can someone please explain this phenomenon? A solid explanation seems to be missing from the entire internet.
5 votes
0 answers
174 views

Why does the tropical year have a ~161 years cycle?

Using PyEphem, I calculated the time difference between consecutive summer solstices in the south hemisphere for the last 4000 years, and plotted them in a graph. It seems like random noise around the ...
2 votes
3 answers
2k views

What effect does Earth losing a part of its mass have, is there an impact on the Earth's orbit around the Sun?

This is a random question that popped into my mind. I'm not a physicist or astronomist, however, I am genuinely curious. Also, this is not intended as a science fiction question, but an actual science ...
8 votes
3 answers
2k views

What precisely leads to planets like COCONUTS-2b to orbit so far away from their host stars, 6000 AU in its case?

Taking our Solar System as an example, most gas giants formed relatively close by (a few AU) and drifted away to reasons I don't know, from an explanation I recall reading. Simply orbiting a few AU ...
0 votes
0 answers
96 views

Difficulty simulating trajectory of moon and sun for Apollo 11 mission

As an engineering student, I am doing a project about Kalman filtering and the mission Apollo 11. Now I tried to simulate the trajectory of the moon and sun for 3 days (the duration in which the ...
-2 votes
1 answer
62 views

Can a star with a stellar mass of 1.176 with a similar composition to the Sun have a planet with these characteristics?

Imagine a solar system similar to ours that has a star with a similar composition to the Sun and a stellar mass of 1.176 and an Earthlike planet with about 1.18 times the mass of Earth in its ...
0 votes
1 answer
77 views

What stellar conditions and orbital distance are needed to produce a year length of 515 Earth days and 9 Earth hours on an Earthlike planet?

A planet has a year length of 515 Earth days and 9 Earth hours. It is the same size and has the same climate as Earth. What stellar conditions would be needed to produce this and what orbital distance ...
1 vote
1 answer
87 views

Which coordinate system should one use for simulating a spacecraft trajectory to the moon? [closed]

Which coordinate system is most suited for this type of problem? ecliptic? equatorial?
3 votes
1 answer
1k views

Is there a significant temperature difference on the moon from apogee to perigee or vice-versa?

Do those few thousand kilometers of difference going around the earth significantly affect the amount of thermal energy the moon receives from the sun to warm up its surface? Also, are there more ...
4 votes
2 answers
4k 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: I have some questions: Does the earth spiral around the sun's path as it is ...
2 votes
1 answer
86 views

largest balanced mass objects in Earth's L4 & L5 Lagrange points?

What is the largest single-object mass that would allow two objects of equal mass to have a stable orbit, one each, in Earth's L4 and L5 Lagrange points?
2 votes
1 answer
895 views

Is there a relation with the noun planet and to be in a plane?

This morning I was in the shower and it struck me that the word planet might be related to the fact that the PLANEts orbit the sun in a PLANE. Did this naming somewhat happen by accident or was it ...
7 votes
3 answers
718 views

What produces gravitational waves with "periods between about 100 - 8000 seconds"?

The Ulysses mission has a compelling story. It was sent to Jupiter to perform a gravitational assist shooting it out of the plane of the ecliptic in order to fly over the Sun's north and south poles ...
1 vote
1 answer
84 views

Calculating Comet Position at a Given Julian Date with Available Orbital Elements

I have some orbital elements for comet P/2004 R1 (McNaught) from this dataset and I would like to calculate its position around the sun (x, y, z coordinates where the sun is at the origin) at a ...
5 votes
1 answer
272 views

Eyeball planets experiencing "catastrophic" flips

This Youtube video by Anton Petrov shows research1 claiming that tidally-locked planets orbiting the same star in tight orbits may interfere with one another and one planet may cause the other to &...
2 votes
0 answers
61 views

Is there an equation that can give position of a satellite around a parent body as a function of time?

I’ve been looking into this lately, and most sources I have used solve this problem numerically. I was thus wondering if there is a proper equation to solve for position without numerical, especially ...
3 votes
4 answers
8k views

Does the Earth constantly lose mass?

The Moon is orbiting the Earth in a circular motion. To keep any object in a circular motion we need energy. Hence, does the Earth lose energy by pulling the Moon? In that case, does the Earth's ...
1 vote
1 answer
373 views

How to calculate solar ecliptic longitude

I would like to write a small script to calculate solar ecliptic longitude in relation to different locations and dates. For instance UTC + - 1...2 etc.. I know, solar ecliptic longitude is the ...
1 vote
1 answer
213 views

Calculating the parameters of binary systems?

If I know the masses of the two bodies (they have equal mass), how do I calculate the two ellipse eccentricities, length of the apoapsis and speed at the apoapsis, that make stable system, as in this ...
2 votes
1 answer
91 views

The possible Masses and Orbits of Hypothetical Moons of Proxima Centauri b

This question asks about the phases of a hypothetical moon of Proxima Centauri b. What phases of a moon orbiting Proxima Centauri b could be seen? And In my answer I suggest that Proxima Centauri b ...
7 votes
2 answers
3k views

Would it be possible for a planet to orbit around a trinary star system in a figure 8 orbit?

I know that it is possible for a 3-body system to be "stable" in a figure-8 pattern. It's only stable if it is set up perfectly with no outside forces, but that's fine with me. If there were ...
5 votes
2 answers
867 views

Will Mercury ever become locked to the Sun?

The Mercury year is between 1 and 2 days. Has it ever been greater, and will it eventually become "tidally locked" with the Sun?
2 votes
1 answer
85 views

Motion equation of a space engine in low-earth orbit

My goal is to simulate the movement/motion of a space capsule from low-Earth orbit with initial conditions emulating an initial thrust. Here is the code, Is it right? I know that the next step is to ...
3 votes
1 answer
394 views

Can such planet orbit 61 Cygni A within a habitable zone?

I have developed a fictional planet I described here in Worldbuilding Stackexchange: https://worldbuilding.stackexchange.com/questions/231162/length-of-seasons-on-a-planet-with-eliptical-orbit. Since ...
6 votes
4 answers
7k views

About how many revolutions has the Earth made around the sun?

The Earth is about 4.543 billion years old. However, the length of a year can be changed by anything from an impact to a natural cycle of orbit changes to a slow drift toward or away from the sun to ...
8 votes
1 answer
122 views

How light could the lightest objects able to exist in a stable orbit be?

Below a certain M1M2, gravity would get so weak that the masses wouldn't be able to orbit each other with stability, as other factors would overwhelm them, even in the quietest, stillest places in the ...
1 vote
2 answers
221 views

Orbital decay of the sun's orbit around Sgr A*: is it likely?

What are the possibilities of the sun orbiting the black hole Sagittarius A* at a very close distance? Is there anything that could possibly alter the solar system's orbit, bringing it much closer to ...
5 votes
3 answers
167 views

Problem with the Orbital Precession predicted by the Relativistic Acceleration equation used in the JPL D440-D441 Ephemerides - please advise

I have previously encountered a problem with the equation used by Yeomans and others for determining the gravitational acceleration of comets (see update in my answer to the previous question Can ...
4 votes
2 answers
513 views

Can General Relativity indicate phase-dependent variations in planetary orbital acceleration?

In a previous question about differences in Newtonian and GTR gravitional force for the case of star-planet gravitational interactions an approximate relationship was noted between the expressions for ...
2 votes
0 answers
63 views

Is there an orbit around the earth that experiences a total solar eclipse by the Moon at least every month?

Is there a way to design an earth orbit so that it passes through the Moon's umbra with greater frequency than total solar eclipses occur on earth's surface? What is the maximum frequency of eclipses ...
6 votes
3 answers
1k views

Was Theia a planet or an asteroid?

According to an article Theia (from the Giant impact hypothesis) was an asteroid and according to The Wikipedia article about Theia Theia was an Earth trojan (which is an asteroid). Which is dubious, ...
4 votes
1 answer
620 views

Observable Speed of objects orbiting a black hole

This is a mostly hypothetical question and thought experiment, and I am aware of some aspects plausibility of it are open for debate. Also, this is Version 2 of the question, as the first question was ...
11 votes
3 answers
288 views

Is there an optimum orbit for a Hipparcos/Gaia-like parallax observatory

The Gaia spacecraft is currently mapping the stars in the Milky Way by parallax. It orbits in the Earth-Sun L2 Lagrange point. The parallax observed from the spacecraft orbiting around the sun allows ...
0 votes
0 answers
71 views

What is the galactocentric aberration?

At the Wikipedia about an aberration, there is the phrase: a recommended galactocentric aberration constant of 5.8 µas/yr What is the galactocentric aberration? How is it calculated correctly? An ...
1 vote
1 answer
146 views

Galaxy plane and Earth's orbit. Connection to seasons?

From my understanding, the Earth (Solar System) crosses a center line of the galactic plane (ecliptic *edit wrong definition, sorry!), while orbiting around the Sun. The Sun also wobbles up and down ...
1 vote
0 answers
474 views

What was this "light" that looked like a star moving repeating from point A to B for about 5 mins [duplicate]

I was looking in the sky one night about 9:45. There was what looked to be a shooting star but much slower and brighter more like a satellite. It was moving (from standing on earth) it looked like a ...
30 votes
6 answers
10k 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 ...
3 votes
1 answer
486 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 ...
4 votes
0 answers
61 views

How long was a year 4 billion years ago, thus how long did it take the Earth to orbit the early Sun? [duplicate]

How long did it take the Earth to orbit the early Sun 4 billion years ago? I'm not talking rotation, which I know has slowed over time. I'm talking about the orbital period of the early Earth. Was it ...
14 votes
5 answers
2k views

Is there any way for a planet orbiting a red dwarf in the habitable zone to not be tidally locked?

Is there any way to avoid the tidal locking of a planet orbiting a red dwarf in the habitable zone? For example, could a planet with a 90° obliquity and large moon avoid such a situation?
2 votes
1 answer
41 views

How can I determine a planet's orbital size if it is moving around an oscillating star?

I'd like to know how to calculate the size of the planet's orbit, given that it is the only one orbiting around a star, and that this star is oscillating with an amplitud of 0.026'' in 25 year periods....
6 votes
1 answer
179 views

Does anybody know how to solve this Earth-Venus-Sun problem?

How can I find (in terms of the angle) the moment when in the system Sun-Earth-Venus, Venus can be seen the most bright if its brightness (flow received in Earth) is proportional to the size projected ...

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