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Objects in orbit pass over the surface above what's commonly called their ground track. For objects in low earth orbit, though they go around the earth every 1.5 or more hours, the Earth rotates beneath them so they don't trace a simple "circle" over the same points on land. The orbit is around the Earth in a fixed plane, so we are likely (but not ...


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you can visit my blog http://dimispoulos.wix.com/dimis for complete documentation and answers to your questions tidal forces from planets act as symmetry breakers on solar mass and are responsible for solar cycles and solar wind


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The USNO Sixth Catalog of Orbits of Visual Binary Stars (ORB6) has the orbital elements you need. $\gamma$ And is WDS 02039+4220 $\alpha$ Gem is WDS 07346+3153 $\zeta$ UMa is WDS 13239+5456 Double star expert Bruce MacEvoy explains orbital elements in maybe enough detail to help you work out some state vectors. My search also turned up a book chapter by ...


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The current explanation for this is something called the frost line (which changes over time). At greater distances from the Sun, a body will receive less and less radiation, and so it will be colder than if it were closer to the Sun. Eventually, conditions become cold enough for volatiles to condense into grains. These volatiles make it possible for ...


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As one gets farther from the sun, the gravity from the planets themselves becomes relatively stronger. So if a body were in an orbit between, for example, Jupiter and Saturn, those two planets would soon make the intermediate body's orbit change. This is conceptually related to the latest definition of "a planet"; A planet must clear its general vicinity of ...


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When the solar system formed, there was an accretion disc, spinning around the newborn Sun. The Sun was emitting radiations, which pushed the lighter materials of the accretion disk (gases) further away, and kept the heavier materials (rocks) much closer. This is why gas giants are almost always further away than rocky planets. Almost. In the case of ...


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The Earth moves in an elliptic orbit around the sun (or around the barycenter). If, in helocentric coordinates the Earth is at position (x,y), then in Geocentric coordinates the position of the sun is in position (-x,-y) So the locus of the Sun in Geocentric coordinates exactly matches the locus of the Earth in Heliocentric. The path of the sun in ...


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I know they will be orbiting about a common center of mass, i.e. the barycenter. But, do the velocities have to be equal in magnitude and opposite in direction (normal to R when R is their distance from each other) for the orbit to be stable? The orbital velocities do not have to be and in general are not equal in magnitude. What is equal is the ...


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There's a mistake in the book (see page 280 on google books): the values for $\lambda_{ecl}$ and $\phi_{ecl}$ should be swapped. Your result is correct: $$ -6338.688^\circ\text{ mod } (360^\circ) = -218.688^\circ, $$ which is the value that is erroneously listed under $\phi_{ecl}$.


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As far as I know, the system with the most stellar members is the black hole at the center of the Milky Way with 8 stars in close orbit. Of course, David Hammen is correct, and if there are other orbiting stars with much longer periods we'd have trouble determining their orbits until they started their close approaches. At the other extreme, is a galaxy a ...



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