# Tag Info

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I think you're not too far from understanding the formula. However, there are a couple details you're missing: From what I understand from the document you linked to, $t_0 = t_{oe}$ is the time at the beginning of the week, or reference epoch. When computing an angle from a angular velocity, you usually need to compute it with respect to an initial angle ...

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Earth's center of mass must be at one of the two focus points of a satellite's elliptical orbit, or at the center of a circular orbit such as a geostationary orbit. One cannot orbit a certain latitude, except for the equator. But there are clever alternatives for different purposes. Geosynchronous (as opposed to geostationary) orbits mean that the satellite ...

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Do geostationary satellites need to have the equator as the plane of rotation, and the earth's centre to be the centre of rotation? To be stationary above a point, yes. Can it rotate over, say, the Tropic of Cancer, focusing on a single city? If the satellite's orbit touched the Tropic of Cancer, it would not be geostationary since the orbit ...

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You cannot point an antenna with a fixed orientation at a satellite that is not in a geostationary orbit. So to get satellite tv you'd not only need a bunch of satellites in orbit instead of one, but every receiver would need probably at least a couple of dishes on complex and highly accurate alt-az mounts.

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If you go far enough north or south, you will reach a latitude where the moon can be below the horizon for several days, just like the 'midnight sun'. It can also be above the horizon for several days for the same reason. At the north or south poles, the moon may be either continuously above or below the horizon for nearly 2 weeks at a time.

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We DO have 2 summers and two winters - and 2 springs and autumns too. The varying distance between the sun and earth does not cause the seasons. They are caused by the tilt of the Earth towards the sun in summer and away from the sun in winter. The northern and southern hemispheres both have the same seasons, but at opposite times of the year. For ...

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This question was once valid, but as of 1994 we found out that our Solar System is part of the Sagittarius Dwarf Elliptical Galaxy, or Sag-DEG (M54), which is the largest of the 30 or so Dwarf galaxies orbiting the Milky Way. We are in a 500 million year long circum-polar orbit. The two apsides are very far above the equatorial plane of the Milky Way. We ...

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Ok, it makes a lot of sense that the gravity of the disc of the Milky Way is pulling stars up and down as they go about their circum-galactic orbit. But this wouldn't explain why recent 3-D observations of the nearest stars using the FLAMES-GIRAFFE spectrograph on ESO’s Very Large Telescope and the IMACS spectrograph at the Las Campanas Observatory showed a ...

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This is a fun question, so I spend some time thinking about it. This is what I came up with. Is this possible? Yes, this is certainly possible. Just consider the Solar System itself. We have a massive central body, the Sun, and several tiny subsystems (planets with their moons) orbiting it. Is it stable? Again, from the simple observation that the ...

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