1. Bell Ringer
What is the difference between Geocentric and Heliocentric?
Geocentric – Earth centered solar system
Heliocentric - Sun centered solar system

2. Chapters 3 & 4 GSE

3. Video

4. Comets, Asteroids, and Meteors
Comets contain a nucleus (rock) and they are surrounded by dust and ice
Comets have orbits that they follow

5. comets Comets have an atmosphere called – coma
Comets gas tails always points away from the Sun
Comets dust tails always follow behind the comet

6. comets

7. comets Halley’s comet is one of the most famous comets.
It passes Earth every years
Last appeared 1986
Next appearance 2061

8. Asteroids Asteroids: Are considered minor planets
Or possibly debris from protoplanets
Many asteroids are located in the asteroid belt between Mars and Jupiter
Average size 1 Km in Diameter

9. asteroids

10. meteoroids Meteoroids can be considered ‘space trash’
Size – dust particle to 10 meters in diameter
Meteoroids - located in space
Meteors – in Earth’s atmosphere (shooting stars)
Meteorites – reach Earth’s surface

11. Man made ‘space trash’
More than 8000 objects have been launched into space.
Some have returned to Earth

12. Rotation and revolution
Earth’s rotation about the 23.5 degree tilt from north pole to south pole.
A complete rotation takes 24 hours (1 day)
Speed at the equator is 1600 km/hr
Revolution around the Sun takes 365 days (1 year) to complete the orbit
Speed 106,000 km/hr

13. Rotation and revolution

14. Seasonal changes (Draw diagram)

15. 12 Zodiac from 88 constellations

16. Close
Do the Northern and Southern hemisphere have the same seasons at the same time?
No – Northern and Southern hemisphere have complete opposite seasons

17. Bring your electronics