A Family of Planets Chapter 21 Section 1 The Nine Planets

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

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

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

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

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

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

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

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

Section 2 The Inner Planets Pages 648-653

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)

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

Mercury

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

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. http://www.nasa.gov/multimedia/videogallery/index.html?media_id=18133414

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

Venus Earths Twin Similar size mass composition distance from the Sun

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

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

Mars: Our Intriguing Neighbor Two mars moons

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

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.

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.