1. Section 17.2
The Planets

2. Terrestrial Planets
A Terrestrial planet that is composed primarily of silicate rocks or metals

3. Mercury
Has a 88 day year
Has temperature of 430 degrees Celsius at the equator.
Very low gravity and a very thin atmosphere

4. Venus Similar in size to earth
Due to atmosphere, it is 460 degrees day or night.
Rotates very slow days to rotate on its axis
Has a thick atmosphere which raises the temperature
The surface is covered with volcanoes

5. Earth
Where you live!
Earth's atmosphere and temperature allow water to exist as a liquid.
Earth is dense allowing it to have relatively high gravity which holds it's atmosphere in place.

6. Mars The most earthllike
The reddish color comes from the "weathered" iron rich rocks that are on the surface
Mars has a very thin atmosphere
Mars has evidence of once having liquid on it's surface
Mars has seasons

8. Gas Giants Planets
A Gas Giant planet consist mainly of liquid hydrogen and helium

9. Jupiter Largest most massive planet
Jupiter rotates rapidly - one day on Jupiter is less than 10 Earth hours
Great Red Spot - a huge storm that rotates like a hurricane - first observed in 1664
Jupiter has 63 moons - Jupiter has the mass and gravity to hold over 1300 earth moons

10. Saturn Largest and most visible rings Rings are made of rock and ice
Saturn has the largest atmosphere of all the planets
Saturn is less dense than water and would float on water
Saturn has at least 30 moons

11. Uranus
Uranus's atmosphere is composed of lots of methane which gives it a blue color
At least 20 moons
Has rings but are not as visible as Saturn's
The axis of Uranus rotates at a tilt of more than 90 degrees

12. Neptune 165 years to make one revolution around sun
Blue color from methane atmosphere

14. Dwarf Planets
A dwarf planet is an object orbiting the Sun that is large enough to be rounded by its own gravity but is not gravitationally dominant in its orbital area and is not a moon.

15. Pluto Smaller and more dense than the other planets
Rotates on a 90 degree axis like Uranus
Pluto has a single moon, Charon
Pluto was demoted to a dwarf planet in 2006

16. Ceres
Located in the asteroid belt

17. Eris
Located in the Kuiper belt (Beyond Pluto)

23. Other Parts of our Universe

24. ASTEROIDS
Large rock masses that orbit the sun, from the asteroid belt

25. COMETS
Dusty pieces of ice and rock that vaporize when they pass near the sun; Come from the kuiper belt

26. A small rock that travels through the solar system
METEOROIDS
A small rock that travels through the solar system
METEOR – a meteoroid that burn up in the earths atmosphere
METEORITE – a meteoroid that makes it to the earth’s surface