The Moon Titania

William Herschel discovered Uranus's two largest moons in 1789, naming them Oberon and Titania, the fairy king and queen in William Shakespeare's A Midsummer Night's Dream. The English astronomer William Lassell (1799-1880) discovered Ariel and Umbriel in 1851. Miranda was discovered in 1948. Since then, a further 22 moons have been found. sidereal period 83.8 Earth years > Temperature at cloud tops -345 F (-210 C) Rotational period 17 hr 14 min Mean distance from the sun 1.785 billion miles...

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Telescopes 7, 23, 27, 62, 64, 65 infrared 62 invention 20, 21, 22 microwave 66 optical 24-25, 27, 28-29, 32, 64 radio 27, 32-33, 46, 62, 71 solar 27, 38 space 7, 65 tidal force 40, 45, 71 Tombaugh, Clyde 57 transit of Venus 28, 46 ultraviolet radiation 32, 43, 48, 71 Ulugh Beigh 10 universe 11, 13, 18, 62-63, 66-67 geocentric 11, 17, 18, 19 heliocentric 18, 19, 20 Uranus 24, 54-55, 56 orbit 36, 37 variable stars 61, 62 Venera probes 47 Venus 7, 8, 40, 42, 46-47 asteroid belt 58 orbit 36, 37...

Messenger To Mercury

In 2004, NASA launched the Messenger spacecraft to explore Mercury. After flying past Mercury three times, it will go into orbit around the planet in 2011. It is the first mission to Mercury since Manner 10 in 1974-75. These blocks wood, aluminum, and iron all have the same volume, that is they occupy the same amount of space. Despite being the same size, however, these materials do not have the same mass and density, nor do they weigh the same. This is also true of the planets. For example,...