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In the absence of the lighting levels in cities, there are a number of objects in the night sky that are easily seen to move against the background of stars: the Sun, the Moon, Venus, Jupiter, Saturn, Mars and Mercury. These are obvious to anyone who looks at the sky regularly from any dark sky site on clear nights, like most places in the pre-industrial ...


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As Wikipedia notes, Since the word 'inclination' is used in exoplanet studies for this line-of-sight inclination then the angle between the planet's orbit and the star's rotation must use a different word and is termed the spin-orbit angle or spin-orbit alignment. In most cases the orientation of the star's rotational axis is unknown. As of now ...


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1. Ancient cultures observed the sky Night skies are naturally dark and there was no light-pollution in ancient times. So if weather permits, you can easily see a lot of stars. No need to tell about the Sun and the Moon. Ancient people had good reasons to study the night skies. In many cultures and civilizations, stars (and also the Sun and the Moon) where ...


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In fact there is no official definition of a satellite. Issac Asimov makes a good argument that the Moon is a planet since its orbit is convex around the Sun for its entire orbit, unlike the other moons of the solar system which are concave when in opposition and convex (to the Sun) when in conjunction. Additionally, the idea that a body is a satellite of ...


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Since I'm a hobbyist, I usually wait to see if someone a bit smarter wants to answer first, but I can give a couple thoughts on this. Hot Jupiters are thought to have migrated inwards, implying that another giant planet has been ejected in order to conserve the orbital momentum of those planetary systems. In the article you posted (I'll pull the ...


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NASA mission data is archived at a handful of NASA archives. If you do not know which archive a data set is in, then you can search the Master Catalog at the NASA Space Science Data Coordinated Archive (NSSDC). The main astrophysics archives are: HEASARC (High Energy Astrophysics Science Archive Research Center) IRSA (Infrared Science Archives) LAMBDA ...


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Horizons Ephemeris Generator Here is a screen capture where vector option is chosen:


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There's a few parts to this question, I'll give it a shot. Also, since you're asking about the geothermal energy of the earth, I'm going to ignore radiation from space and radioactive van allen belts (Jupiter has a very radioactive van Allen belt). Also, as voyager discovered when it left the solar system, there's more radiation in the form of cosmic rays ...


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The wikipedia page you linked to tells you that the solar system is gravitationally "chaotic", in part because the mass of the sun is not fixed over time. But even more simply than that, focusing just on the gravity (ignoring loss of stellar mass, etc.), the solar system is an N-body problem. We have 8 planets, a sun, and millions of asteroids, comets, and ...


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A simple argument why the gas cloud orbiting the Protosun formed a disc is as follows. There are two characteristic properties of this gas cloud: its total energy and its total angular momentum. While the angular momentum is conserved, the energy it not: radiation reduces the fluid temperature and hence the energy. So eventually, the cloud settles to a ...


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Your final three questions: Should the supplementary Q&A sheet considered as legimate official definitions, or should it be considered as a one way of interpreting the Resolution B5? That supplementary Q&A absolutely should not be considered as legitimate official definitions. That Q&A pertains to the original draft of the resolution. The ...



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