A History of Discoveries in the Solar System jdogbrunner@yahoo.com

1. Adapted from http://en.wikipedia.org/wiki/Timeline_of_solar_system_astronomy

2. Antiquity

2.1. The Venus Tablet of Ammisaduqa, which describes the motion of Venus, is compiled in Babylon

2.2. Babylonian astronomers identify Venus, Mercury, Mars, Jupiter, and Saturn

2.3. 350 BC, Aristotle sites lunar eclipses as evidence that the earth is spherical

2.4. Ptolemy codifies the geocentric model of the Solar System

3. Middle Ages

3.1. 500, Indian astronomer Aryabhata accurately computes the Earth's circumference

4. Renaissance

4.1. 1543, Nicolaus Copernicus publishes his heliocentric theory

4.2. 1609, Johannes Kepler states that the planets' orbits are elliptical

4.3. 1610, Galileo Galilei discovers Callisto, Europa, Ganymede, Io, and Saturn's rings

4.4. 1655, Giovanni Cassini discovers Jupiter's giant red spot

4.5. 1656, Christiaan Huygens discovers Titan

5. 18th Century

5.1. 1705, Edmond Halley publicly predicts the periodicity of Halley's comet

5.2. 1781, William Herschel discovers Uranus

6. 19th Century

6.1. 1801, Guiseppe Piazzi discovers Ceres

6.2. 1846, Johann Galle discovers Neptune

6.3. 1862, Father Angelo Secchi determines that the sun is a star

6.4. 1877, Asaph Hall discovers Deimos and Phobos

7. 20th Century

7.1. 1930, Clyde Tombaugh discovers Pluto

7.2. 1946, An American camera-equipped rocket provides the first picture of Earth taken from space

7.3. 1959, Luna 3 takes the first pictures of the dark side of the moon

7.4. 1966, Luna 9 provides the first pictures from the surface of another celestial body

7.5. 1969, Humans land on the moon

7.6. 1971, Mariner 9 orbits Mars and reveals the planet's typography

7.7. 1978, James Christy discovers Charon

7.8. 1990, The Hubble Telescope is launched

8. 21st Century

8.1. 2005, Eris is discovered

8.2. 2006, Pluto is reclassified as a dwarf planet