Solar System

6th Grade Science

Earth Center

• Greeks– Noticed that dots in sky moved• Called them planets (wanderer)

• Romans– Gave these wanderers names of Gods (current names)

• Ptolemy’s Model– Earth as center (Geocentric)– Accepted for 1,500 years (good approximation)

Sun at Center• Heliocentric• Copernican (1543)

– Not accepted easily• Tycho Brahe (1580)

– Orbits could not be circular• Kepler (1601)

– Orbits are Ellipse (Matched observations perfectly)• Galileo (1610)

– Used telescope to show moons circle other planets– Church reacted violently to his work

Planets

• Mercury– Small planet– Dense metal– 430 °C to -170°C

Venus

• Same size as Earth• Hottest planet 460°C average temp.

Earth

Mars

• Same as land area on Earth• -87°C to -5°C

Jupiter

• Gas giant (spot)• -148°C

Saturn

• Gas Giant (largest rings)• -178°C

Uranus

• Gas Giant (Strange orbit)• -216°C

Neptune

• Gas Giant• -214°C

Pluto

• Not a planet (size of our moon)• Not in same plane as rest of planets (Comets)