1. Astronomy

2. List what you know about astronomy so already.

3. Objects seen in the sky that are not connected to Earth or its atmosphere are called celestial objects. Examples: sun, moon, stars, comets

4. Celestial Motion If you watch the sky, it is clear that it changes over time Objects appear to move across the sky from east to west along an arc shape

5. Models of the Universe Geocentric model – Earth in center of universe Heliocentric model – sun in center of universe, the model we have today

6. Stars Hot, glowing balls of gas.

7. Galaxies Stars within systems of spiral shapes

8. Nebulae Clouds of gas and dust lit up by stars

9. Our Solar System Earth’s sun is an average sized star Light travels at a speed of 300,000 km/sec, meaning that it takes light less than 10 minutes to be seen from Earth

10. Planets Planets are bodies that are at least partly solid, orbit the sun, and give off mainly reflected sunlight. My Very Educated Mother Just Served Us Nachos Mars, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune

11. Terrestrial Planets The four innermost planets that are small and dense Mercury, Venus, Earth, Mars

12. Jovian Planets The four large planets that are less dense Jupiter, Saturn, Uranus, Neptune Gas giants

13. Asteroids Solid bodies having no atmosphere that orbit the sun. Most are in-between Mars and Jupiter Meteors are chunks of matter that enter an atmosphere and give off light

14. Comets Comets move in elliptical orbits, but they are more elongated paths than planets Ball of ice that heats up and turns into a cloud of gases

15. Motion in the Solar System The force that keeps planets in orbit around the sun is gravity. Gravity keeps moons orbiting around the planets.