1. A Family of Planets Chapter 21
Section 1 The Nine Planets

2. Log: Oct.8
What is our solar system?
What is it made of?

3. Planet- means “wanderers” ancient astronomers knew they were physical bodies and could predict movement

4. Measuring Distances
Astronomical Unit: (AU) the average distance between the sun and earth
150,000,000 km= 8.3 light minutes
Light from sun take about 8mins to travel to planet earth

5. Measuring Distances Speed of Light: 18,000,000km per minute
light minute or Light hour

6. Inner Planets (Mercury, Venus, Earth, and Mars) More closely spaced
Terrestrial- Means rocky

7. Outer Planets Known as Gas giants
Pluto is dwarf planet and exception to the rule

8. Log: Oct 9
Name some differences between inner and outer planets

9. Log: Oct.13th
Why are the outer planets called the Gas Giants?

10. Section 2 The Inner Planets
Pages

11. Key Words Revolution- the motion of a planet orbiting another
Period of revolution- The time it takes the planet to orbit the sun (year)
Orbit
Period of Rotation- the time it takes a planet to rotate on its axis (day)

12. Log: Oct. 14
What does the period of revolution and period of rotation tell me about a planet

13. Mercury

14. Mercury : Closest to sun
Facts
Name and speed
The smallest planet in our solar system.
Lacks Atmosphere so temperatures are extreme
430 degrees Celsius
-170 degrees Celsius
No known Moons
Spacecrafts
Mariner 10
MESSENGER
Greek God Mercury do to the speed of its revolution
Mercurian 1 Year= 88 Earth days
Mercurian 1 day = 59 Earth Days

15. Mercury is the closest planet to our Sun
Mercury is the closest planet to our Sun. It is named for the ancient Roman god of trade and profit. Legend says Mercury's winged sandals gave him super speed. Mercury the planet is super fast, too. It zips around the Sun every 88 days - faster than any other planet. No wonder it got its name from the quickest of the ancient gods.

16. New Key Words Prograde-spins on axis counterclockwise
Retrograde- spins on axis clockwise

17. Venus
Earths Twin Similar
size
mass
composition
distance from the Sun

18. Venus Facts Venus has no moon and no rings. 1Venus Day=243 Earth days
2nd planet from our Sun
Named for the Roman goddess of love and beauty.
brightest planet in the night sky.
Surface is hidden beneath hot, poisonous air
made up mostly of carbon dioxide
clouds of sulfuric acid,
hurricane-force winds and lightning.
Venus has no moon and no rings.
1Venus Day=243 Earth days
1Venus Year= 224 Earth Days

19. Earth :An Oasis
3rd Planet from Sun
Water
known to harbor life

20. Mars: Our Intriguing Neighbor
Two mars moons

21. Mars 4th Planet from Sun Spacecrafts Moons
Viking 1 &2
Mars Pathfinder
Moons
Very low pressure so no liquids present
Evidence mars had water in past
Temperature
Frozen Ice Caps of water and CO2
'Red Planet' because of its red soil

22. How Mars Got it’s Name The planet is named for the Roman God of War.
It has two moons, Phobos (fear) and Deimos (panic).
The moons get their scary names from the horses that pulled the chariot of the Greek god Ares.

23. Olympus Mons on Mars: The Largest Volcano
The largest volcano in the Solar System is on Mars. Olympus Mons rises 24 kilometers high and measures 550 km across. By comparison, Earth's largest volcano, Mauna Loa in Hawaii, rises 9 km high and measures 120 km across.