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radioactive age dating
radioactive age dating

... • The planets, satellites, comets, asteroids, and the Sun itself formed from the same cloud of interstellar gas and dust • The composition of this cloud was shaped by cosmic processes, including nuclear reactions that took place within stars that died long before our solar system was formed • Differ ...
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... the heavens and the earth” refers to a long period of time that the universe we see in the heavens developed according to God’s design. Apparently the fine tuning of the laws of nature, the physical constants, the initial density and rate of expansion of the universe God established was sufficient o ...
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... Click on “PLANET PIT STOP” at the bottom of the page. Click on “Check in at the Weighing Station. Enter your Earth weight then click calculate. On which planet would you weigh the most? ___________________ On which planet would you weigh the least?___________________ What is the difference between y ...
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... Remember how we talked about how stars have things revolving around them? Planets are one good example. Earth is a planet, and there are seven other planets in our solar system that all revolve around the sun. Mercury is the closest planet to the sun, and it's the smallest of the eight. Venus is the ...
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... Uranus is usually one smooth color, but light and dark areas often appear on Neptune. Clouds of methane ice crystals can form high enough in the atmosphere of Neptune to look white. Storm systems can appear in darker shades of blue than the rest of the planet. One storm, seen during the flyby of the ...
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... Newton’s laws of motion and law of gravitation can be used to explain the forces, position and motion of all objects in the universe. A simple analogy of how gravity controls the motion of a planet around the Sun can be shown by a mass on the end of a string being spun around in a horizontal plane a ...
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... Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. It has the longest rotation period (245 days) of any planet in the Solar System, and, unusually, rotates in the opposite direction to most other planets. It has no natural satellite. It is named after the Roman goddess of l ...
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Definition of planet



The definition of planet, since the word was coined by the ancient Greeks, has included within its scope a wide range of celestial bodies. Greek astronomers employed the term asteres planetai (ἀστέρες πλανῆται), ""wandering stars"", for star-like objects which apparently moved over the sky. Over the millennia, the term has included a variety of different objects, from the Sun and the Moon to satellites and asteroids.By the end of the 19th century the word planet, though it had yet to be defined, had become a working term applied only to a small set of objects in the Solar System. After 1992, however, astronomers began to discover many additional objects beyond the orbit of Neptune, as well as hundreds of objects orbiting other stars. These discoveries not only increased the number of potential planets, but also expanded their variety and peculiarity. Some were nearly large enough to be stars, while others were smaller than Earth's moon. These discoveries challenged long-perceived notions of what a planet could be.The issue of a clear definition for planet came to a head in 2005 with the discovery of the trans-Neptunian object Eris, a body more massive than the smallest then-accepted planet, Pluto. In its 2006 response, the International Astronomical Union (IAU), recognised by astronomers as the world body responsible for resolving issues of nomenclature, released its decision on the matter. This definition, which applies only to the Solar System, states that a planet is a body that orbits the Sun, is massive enough for its own gravity to make it round, and has ""cleared its neighbourhood"" of smaller objects around its orbit. Under this new definition, Pluto and the other trans-Neptunian objects do not qualify as planets. The IAU's decision has not resolved all controversies, and while many scientists have accepted the definition, some in the astronomical community have rejected it outright.
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