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

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-6
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1answer
115 views

Is this Universe scenario correct? [closed]

I will try to give you my reasoning behind my scenario. Ok I've researched and found That 95 percent of the galaxy has been formed already, And the other 5 percent is still to come.http://www....
8
votes
2answers
189 views

Lack of objects between heliopause and Oort cloud?

If we take a look at a logarithmic scale of the Solar System, there appears to be a large gap between the heliopause and the Oort cloud: Why is that? There are some objects in the gap, but why are ...
3
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1answer
81 views

Stability of orbital resonance

Recently I've become more interested in the topic of the stability of planetary systems. I have been reading about it and it seems that orbital resonances play an important role in the stability of ...
5
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1answer
112 views

How were the orbits of planets first mapped out?

I'd like to know how the orbits of planets were first 'mapped out' and to understand the maths behind it. e.g. How do we know what position in space a planet will be at certain time so that spacecraft ...
5
votes
2answers
213 views

Are there ever any simultaneous transits of both Mercury and Venus as seen from the Earth?

Transits of Mercury happen fairly frequently due to its short period, but transits of Venus are less frequent. I've looked over the data available to me and found that there have been transits of ...
2
votes
1answer
131 views

Do all planets rotate in the same direction in relation to each other?

In other words, does everything spin counterclockwise according to their axes (in relation to each other)? I suppose my question goes for stars, moons and other objects too. But then again, all you ...
1
vote
3answers
56 views

What is the centre of rotation of Pluto?

I know that Pluto and Charon have been found to circle round each other, hence the reason Pluto is no longer a planet I believe, which would mean that the centre of rotation is an arbitrary (!) point ...
2
votes
1answer
174 views

Are there accurate equinox and solstice predictions for the distant past?

I am trying to find information on the equinox/solstice dates before 1600, more exactly referring up to 10,000 BCE so as to create a sort of calculator on an Excel spreadsheet. I have read about the ...
0
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0answers
22 views

Accuracy of Laplace Method for determining orbital elements

Recently I had to implement Laplace method and apply it to 3 observations of Mars (10 days in between two observations). The results were pretty good, with discrepancies with real data well below 5% ...
1
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3answers
45 views

Is the duration of a sidereal year stable?

According to this essay by Phil Plait, the duration of Earth's sidereal year is 31,558,149 seconds. Is this figure stable? If I were to meaure Earth's orbit several million (or billions) of years in ...
3
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2answers
112 views

Why doesn't Jupiter increase the chances of an asteroid to strike the Earth?

I often hear the hypothesis that Jupiter decreases the chances of an asteroid strike on the Earth, but my question is, why does it only decrease the chances ? While Jupiter can deflect some ...
11
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3answers
770 views

Is there any point on earth where the moon stays below the horizon for an extended period of time?

When I was teaching a class why the earth has seasons today, I mentioned how the poles of the earth experience months of daylight and darkness. Then one of my students asked whether the moon ...
1
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0answers
69 views

How to get the longitude of the perihelion to find the Heliocentric Equatorial coordinates of a planet

I'm writing a program to randomly generate star systems and I have been having a difficult time figuring this out. I've found the equations I need to get the heliocentric equatorial coordinates, but I ...
1
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2answers
112 views

Can planets have orbits other than elliptical or circular orbits?

Can planets have orbits other than elliptical or circular orbits? All of the planets in our solar system have either a circular orbit or an elliptical orbit (perhaps like Pluto).
4
votes
1answer
77 views

How to cool down a moon?

I'm doing an Astronomy project and need to terraform a moon. It is about the size of Mars and orbits a gas giant which is at a distance of 1.28 AU of its star. I though about putting a sunshade at the ...
10
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3answers
3k views

What if Earth and Moon revolved around each other like Pluto and Charon?

What would be different for us if Earth and Moon revolved around each other like Pluto and Charon do?
4
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1answer
121 views

Simulate an orbit with orbital elements

I want to simulate the orbits of the planets from our solar system. I want to use orbital elements to calculate the current position(xyz) at a time t. The simulation doesn't have to be too exact, but ...
3
votes
1answer
87 views

Calculate apsides without knowing eccentricity

How would one go about determining the apsides of an orbit, knowing only the current distance between the 2 bodies, the orbital velocity, and the period? Every formula I've seen requires eccentricity, ...
6
votes
2answers
167 views

How do I calculate the positions of objects in orbit?

In a model of the solar system, given the Sun is at the point $(0, 0, 0)$, an given the six orbital elements for each object in orbit ($a$, $\epsilon$, $i$, $\Omega$, $\omega$, $M_0$), how can I ...
4
votes
1answer
97 views

Ambiguity in Earth's “Tilt”

It’s well-known that the axial tilt of the Earth (with respect to the ecliptic) is about 23.4 degrees. However, two angles is needed to specify the orientation of any rigid body, so it’s unclear to me ...
2
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1answer
145 views

Can a star orbit around multiple planets or a planet with massive moons?

Note: I'm not talking about a star orbiting around a single or lonely planet :) I know a star orbiting a planet is almost impossible because if a planet is more massive than a star, that "planet" ...
2
votes
2answers
93 views

Alignment of Semi-Major Axis of Orbits

So I'd like to ask whether the semi-major axis of planetary orbits are aligned? Logically, they shouldn't be, but many websites act as if they are. If they're not aligned, what's the angle between the ...
4
votes
1answer
54 views

How (un)stable are the Lagrangian points 1, 2 and 3?

A couple questions, please: I know that the Lagrangian points 1, 2 and 3 are unstable and special Lissajous orbits plus some station-keeping are required to place a spacecraft around them. But I was ...
4
votes
1answer
40 views

Why do spectroscopic binaries have approximate circular orbits?

So for an assignment I have to answer the question what I can conclude concerning the shape of the orbit, knowing that it is both an eclipsing and spectroscopic binary. Now, I think the answer I ...
6
votes
2answers
756 views

When was the term “orbit” (in the modern sense) first used and by whom?

Wikipedia coyly suggests that some notions and views kept circulating (apparently since Adam and Eve) until finally Kepler, of all people, ... etc. I find this hard to believe. Please elucidate.
3
votes
1answer
62 views

Is the size and heat of a star important in the development of a solar system?

How do the size and heat of stars affect development of solar systems and what kinds of planets can develop? Is it possible to orbit supermassive stars? Furthermore, would star's unleashing violent ...
3
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1answer
127 views

Does the Sun orbit the Milky way in a (kind of) flat or inclined orbit or more of a sine wave? [duplicate]

I know it can't be a perfect ellipse or smooth orbit due to all the matter in every direction, and our Sun could be affected by a gravity assist of sorts if it passes close enough to another massive ...
2
votes
2answers
193 views

Precessing of the Earth

It's been known that the Earth's axial tilt varies from 22.5 to 24.5. Does this result in a wobbling while the value of the tilt varies about these two limits? If so, how does it affect the mechanics ...
1
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2answers
136 views

Stellarium 0.10.4: planet orbits change over time?

If I draw the orbit of Mars in stellarium 0.10.4 for 23 Sep 2015, it passes south of Chi Leonis: If I advance the date to 17 Oct 2015, however, the orbit of Mars correctly goes right through Chi ...
6
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4answers
578 views

Moon's orbit around the Sun

The Earth revolves around the Sun and the Moon revolves around the Earth. Out of curiosity I started thinking about the orbit of the Moon around the Sun and expected (assumed) it to be as follows: ...
1
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2answers
49 views

Two body transient solution

In the two body problem, if each body is given an initial condition as a momentum vector, what is the transient part of the solution as it settles into the steady state orbit?
6
votes
1answer
164 views

Best approximation for Sun's trajectory around galactic center?

What is the current best approximation for the path the Sun takes around the center of the Milky Way? I have found some information on the approximate position of the Milky Way's center, the speed of ...
2
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1answer
67 views

Do orbital resonances always form naturally?

For example, if I throw two planets to orbit a star at random direction, would they form an orbital resonance?
3
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1answer
244 views

How long does it take Dawn to orbit Ceres?

I haven't been able to find the orbit time of Dawn around Ceres. Do you know how long it takes?
2
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2answers
133 views

Could an asteroid knock the moon out of its orbit?

As describe in this CNN article, an asteroid is going to pass near the Earth on Halloween. The article says that As it misses Earth by about 300,000 miles (slightly farther away than the moon), ...
1
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5answers
512 views

Does the Sun turn around a big star?

The moon turns around the Earth. The Earth turns around the Sun. Does the Sun turn around a big star? If so, does this big star turn around a very big star? ... etc ... What are all the intermediate ...
8
votes
5answers
971 views

When will all eight planets in our solar system align?

Ignoring expansion of the universe, entropy, decaying orbits, and interference from any bodies colliding with or otherwise interfering with their orbits, will the eight planets known planets in our ...
2
votes
2answers
67 views

Can a probe orbit Pluto given Charon's gravity?

Is it possible for a man-made probe to orbit Pluto given its closeness to Charon? The gravitational field interaction of Pluto and Charon is likely to make simple orbit structure difficult for a man-...
0
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1answer
86 views

What causes objects to become tidally locked?

I'm trying to write a gravity simulation (suns planets etc), and was hoping tidal locking could be one feature demonstrated. Using a simple equation for gravity has produced some interesting results, ...
2
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0answers
135 views

Is there a web service providing orbital data of solar bodies (planets, comets, asteroids, dwarf planets)?

I would like to be able to connect to a web-service and retrieve JSON data containing information on current (as of today or so) orbits of planets, comets, asteroids, and dwarf planets in our solar ...
9
votes
3answers
780 views

How does a gravity slingshot actually work?

From what I know of elliptical orbits, an object speeds up near the periapsis and slows down at the apoapsis, much like we learned in high school physics how a sphere would roll down and back up a ...
4
votes
1answer
203 views

How is it that all planets (and moons) in our solar system are in equilibrium orbits?

Previously, I was told that in order for any bodies to orbit each other for over a long period of time, the orbital period, distance and masses have to be precisely matched such that the bodies won't ...
4
votes
1answer
5k views

Average amount of annual daylight at any place on earth

If this is the wrong group please direct me to the correct one. It seems intuitively obvious that the amount of daylight per annum should be the same for any latitude on earth. For example, 12 hours ...
6
votes
4answers
518 views

Does Sun have a reflection on Earth?

The new Google Maps1 presents an actual view of Earth, with the current position of Sun illuminating half part of Earth in real time. It is quite an exquisite view. My question is based on the ...
0
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1answer
60 views

How to get from the earth to another planet/ the moon? What happens on the way? [closed]

I have a problem explaining for my students how to get from the earth to the moon? Is there someone who can give a good explanation? I Think these are words that might be included. Escape velocity, ...
2
votes
1answer
161 views

Should a station in orbit around the Sun travel in the same or the opposite direction to the planets?

If we put a station in orbit around the Sun, and wanted to send transports as regularly as possible without the travel costs being prohibiting; should we have it rotate around the Sun clockwise, or ...
3
votes
1answer
124 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 ...
10
votes
4answers
2k views

How can we avoid needing a leap year/second?

Given the Earth's current speed around the sun and current rate & axis of rotation, what is the best way to keep time to avoid a leap year? How many hours should we have in the day and days in a ...
2
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2answers
197 views

How many satellites orbit the Earth? At what rate do they orbit the earth? [closed]

I was looking at a full moon the other night with my telescope and noticed a black dot move across the moon quite rapidly. This happened a few times and others who were with me were able to confirm. ...
0
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1answer
95 views

Can Pluto and Neptune collide anytime in future? [duplicate]

We know that, the orbit of pluto ambiguously cuts the orbit of Neptune. I want to know, whether the revolving speed of Neptune is equal to the revolving speed of pluto. If not, is there a possibility ...