Science 9 — What have we been doing all year? 1. Scientific Ways of Knowing and Scientific Inquiry 2. Chemistry (physical/chemical change, atoms (protons, neutrons, and electrons), compounds/molecules, and chemical reactions 3. Physics (energy, PE, KE, transformations of energy, velocity (speed + direction), Newton ’ s Laws, and forces*

Science 9 — Will it ever end? 4 th quarter — EARTH SCIENCE Outer space — our solar system and all of its contents (stars, planets, and their satellites) Where did the universe come from? Layers of the Earth (Plate Tectonics) The Earth as a System (atmosphere, biosphere, lithosphere, & hydrosphere) Innovators of Science*

Chapter 19 The Solar System Sun, Earth, and Moon The Inner and Outer Planets Formation of the Solar System

Imagine you went on a trip to the moon. What would you take with you? Why would you choose each item? *

1. What is a planet? Any large object that orbits the sun or another star There are five planets (besides Earth) that are visible to the unaided eye –Mercury –Venus –Mars –Jupiter –Saturn*

2. Facts about our Sun The sun is a star — closest star to Earth Sun is average size and intensity star Diameter of the sun is 1.4 million km (110 times bigger than the Earth) Mass of the sun is 300,000 times heavier than Earth*

3. Day and Night Day and night occurs because of how the earth spins on its axis. When our part of earth is towards the sun we see daylight When our part of the earth is pointed AWAY from the sun we have darkness*

4. Solar System Includes the sun and all the objects that orbit it Planets Meteoroids Asteroids Comets Gas Dust*

OGT ALERT The next question is exactly what the state wants you to know for your OGT. Study this information carefully!

5. Gravity holds the solar system together The force of gravity between two objects depends upon their masses and distance between them. The greater the masses the larger the gravitational forces between them. The closer two objects are to each other, the stronger the gravitational force between them.

Concept Check Q1 ) Is there gravity in space? A1) Yes all objects are acting on each other Q2) Why do astronauts have a feeling of weightlessness if there is gravity in space? A2) They are in free-fall with earth ’ s gravity pulling on them, but their forward motion along their orbit keeps them from getting closer to earth. *

6. Nine Planets? Planets can be seen because their surfaces reflect sunlight. Orbits of planets are directly related to their distance from the sun Mercury orbits the sun in 88 days Earth orbits in days Pluto 248 years (sometimes crosses in front of Neptune making it the 8 th planet instead of the 9 th )

7. Satellites Object in orbit around a body that has a larger mass What is earth ’ s satellite? The moon is the earth ’ s satellite because the moon has a smaller mass. Larger planets usually have more satellites

8. What holds satellites in place Since mass is related to gravitational pull, it makes sense that larger more massive planets may have more satellites. A few satellites have atmospheres, but most do not.

9. Moon Phases Appearance of different shapes of the moon. Does the moon really change shape? No, but the position of the earth, moon, and sun cause us to see different shapes of the moon. The time from one full moon to the next is 29.5 days.

10. Eclipse Can be predicted and occur when the sun, moon, and earth are in a straight line Solar eclipse= moon casts a shadow onto Earth; within this small shadow area the moon blocks the sun Lunar eclipse = the moon passes into the shadow of the earth; a full moon darkens; this is rare because of the moon ’ s orbit being slightly tilted

11. Tides Coastal areas have two high and two low tides everyday. Tides are mainly due to the gravitational pull of the moon on the water The gravitational attraction is strongest between the side of the earth that is closest to the moon and weakest on the side farthest from the moon.

12. Asteroids Minor planets km in diameter Remember that Pluto ’ s diameter is only about 2300 km

13. UB 313 Confirmed February 1, 2006

14. Nebula Large cloud of dust or gas in space. The most accepted model for the creation of the solar system is by way of a nebula

15. Comets Probably composed of leftover material from when the solar system was formed Dust and ice made of methane, ammonia, carbon dioxide, and water Solar winds blow the dust to make a trail behind the comet

16. Meteors and Meteorites Meteors are small pieces of rock Meteoroids are small pieces of rock that enter earth ’ s atmosphere Meteorites are small piece of rock that survive the atmosphere and hit the ground Most were once asteroids Some may have come from the moon or Mars

17. Craters Meteoroids less than 10 m across usually burn up in the atmosphere. Earth has been hit over 100 times by meteorites. The impact of meteorites cause craters Could a meteorite that was only km wide have caused the extinction of the dinosaurs? This could have released as much energy as 10,000,000 hydrogen bombs