| A | B |
|---|
| planetismals | small asteroid-like bodies; building blocks for planets |
| terrestrial | another name for inner planets |
| Mars | inner planet that once had liquid water |
| heliocentric system | Earth revolves around Sun |
| chromosphere and corona | visible during total solar eclipse |
| outer planets | larger; made of hydrogen and helium |
| geocentric system | planets revolve around Earth |
| Kepler | discovered that each planet's orbit is an ellipse |
| Mercury | smallest inner planet |
| Uranus | similar to Neptune in size; rotates on side |
| photosphere | outer layer of Sun |
| Corona | where solar wind streams from |
| Saturn's Rings | chunks of ice adn rock |
| Galileo | observed Venus goes through phases |
| inner planets | small with rocky surface |
| asteroid belt | between Mars and Jupiter |
| Jupiter | largest planet |
| Big Bang | theory of Solar System formation |
| Meteroids | come from comets or asteroids |
| Nuclear Fusion | how the Sun produces energy |
