Chapter 2 The Solar System

Observing the Solar System Planets: “Wandering Star” Greeks Ideas: We lived in a Geocentric system. (Earth is in the center of solar system)

Copernicus’s Idea 1500’s Heliocentric System – Earth and other planets revolve around the sun. Galileo used telescope to prove heliocentric system idea.

Brahe and Kepler’s Law Orbit of each planet is an ellipse.

Issac Newton Inertia and gravity keep planets in orbit. –Inertia – a moving object continues in a straight line. –Gravity – keeps planet in an orbit

The Sun Interior of the sun 1.Nuclear fusion of H- sun’s energy comes from 2.5 billion years of fuel left

Sun’s Atmosphere 3 layers: 3. Photosphere: inner layer, light comes from 2. Chromosphere – reddish glow seen during an eclipse 6. Corona - outermost

Solar Wind Corona sends out stream of charged particles Creates Auroras (Aurora Borealis)

Antarctica:

Features of the sun Sunspots – dark spots on sun, areas of gas that are cooler than the rest of the sun.

Prominences Reddish loops of gas link sunspot regions

Solar Flares Explosions due to prominences connecting Increase solar wind – magnetic storms

Other objects in Solar System Comets: “dirty snowball” Orbits are long and narrow 3 parts of a comet: –Tail – –Nucleus – –Coma -

Orbit of a comet

Asteroids Too small to be planets Belt between Mars and Jupiter Discovered about 10,000 asteroids Impact Yucatan Peninsula, Mexico

Meteors. Meteoroid: chunk of rock or dust in space. Meteor: A streak of light in the sky produced by the burning of a meteoroid in Earth’s atmosphere Meteorites: meteoroids that pass through the Earth’s atmosphere and hit the Earth’s surface Meteor crater in Arizona

A bright meteor 1998, Florida