Theories Of The Origin Of The Moon :: essays research papers fc

The Moon is the only natural satellite of Earth. The distance from Earthis more or less 384,400km with a diameter of 3476km and a mass of 7.35*1022kg. Through history it has had umteen names Called Luna by the Romans, Selene andArtemis by the Greeks. And of course, has been known through prehistorical times. It is the second brightest object in the sky after the Sun. Due to its coat and composition, the Moon is sometimes classified as a terrestrial " satellite"along with Mercury, Venus, Earth and Mars.Origin of the Moon Before the modern get on of space exploration, scientists had three major theories for the origin of the moon fission from the land formation in populace orbit and formation far from earth. Then, in 1975, having studied moonrocks and close-up pictures of the moon, scientists proposed what has come to be regarded as the most likely of the theories of formation, planetesimalimpact or giant impact theory.Formation by fission from the Earth The modern ver sion of this theory proposes that the moon was spun off from the earth when the earth was young and rotating rapidly on its axis. Thisidea gained support partly because the density of the moon is the same as thatof the rocks just below the crust, or upper mantle, of the earth. A majordifficulty with this theory is that the angular pulsing of the earth, in order toachieve rotational instability, would have to have been overmuch greater than theangular momentum of the present earth-moon system.Formation in circle Near the EarthThis theory proposes that the earth and moon, and all other bodies of thesolar system, condensed self-reliantly out of the huge cloud of cold gases andsolid particles that effected the primordial solar nebula. Much of thismaterial finally collected at the center to form the sun.Formation Far from Earth According to this theory, independent formation of the earth and moon, asin the above theory, is assumed simply the moon is supposed to have formed at a di vergent place in the solar system, far from earth. The orbits of theearth and moon then, it is surmised, carried them beneficial each other so that the moonwas pulled into permanent orbit most the earth.Planetesimal Impact First published in 1975, this theory proposes that early in the earthshistory, well over 4 billion years ago, the earth was touch by a large body calleda planetesimal, about the size of it of Mars. The catastrophic impact blastedportions of the earth and the planetesimal into earth orbit, where debris from the