unit astronomy

Astronomy The Solar System The Solar System is a collection of  A star  Planets  Satellites  Asteroids  Comets Grouping Inferior planets vs Superior planets  I: Closer to the Sun than the Earth –  S: The distance from the Sun is greater Terrestrial planets vs Giant Planets  T: Small, rocky ones  G: Made of gas and very large  Pluto: odd one out, the former satellite of Neptune The Planets travel round the central star (=the SUN) Signs Terrestrial planets Giant planets Satellites:  Smaller rock bodies  All the planets have satellites (at least one each) with the exception of Mercury and Venus  Earth: 1, Mars:  Jupiter: 16, Saturn: 23, Uranus:15, Neptune:8  Five more Apollo missions carried astronauts to the moon before the program ended in 1972 (There were to have been six, but Apollo 13’s mission ended in near disaster.) The last man to leave his footprint on the moon was Apollo 17 commander Eugene Cernan, on Dec 14, 1972 It orbits the common mass centre of the Earth-Moon system every 27,32 days  It does not exactly orbit the Earth  The mass of the Moon is 80 times less than of the Earth!!!  The common mass centre is inside the Earth It has a captured rotation…  = rotation and revolution take the same time  It keeps one face turned all the time towards the Earth (!) It has no light of its own…  It reflects the light of the Sun  It goes through a series of phases  The amount of sunlit side changes during its revolution The most important phases  New Moon (not visible)  First Quarter (resembling the letter D)  Full Moon (all the sunlit side is visible)  Last Quarter (similar to the letter C) The phases repeat themselves every 29,53 days The Moon Eclipses Eclipse (definition)  An event in which light from one body is blocked off by another body  Both the Earth and the Moon reflect the light of the Sun  the Sun and the Moon line up with the Earth Eclipses of the Sun and the Moon can happen ONLY WHEN Lunar eclipse As the Moon orbits the Earth, it may enter the shadow of the Earth at full Moon Penumbra, Umbra Lunar eclipse Solar eclipse The Earth may enter the Moon’s shadow at New Moon Solar eclipse Solar eclipse of November 25, 2011 The total solar eclipse of August 11, 1999 was quite exceptional The reason for this was that the path of totality passed through densely populated areas of Europe [...]... a spacecraft on the moon, in 1959, but NASA’s Neil Armstrong becomes the first human to set foot on the lunar surface, realizing humanity’s age-old dream And effectively winning the space race for the United States