STAAR Review

Category 3-Earth & Space

Students demonstrate an understanding of components, cycles, patterns, and natural events of Earth and space systems.

8.9A

Plate Tectonics History

1 st : Wegener’s theory of Continental Drift— continents move slowly from Pangaea to present 2 nd : Sea Floor Spreading—magma wells up forcing the sea floor apart & forming mid-ocean ridge (convection currents) 3 rd : Theory of Plate Tectonics—Earth’s crust is broken into parts called plates that move or “float” on top of the mantle

8.9A

Sea Floor Spreading

Sea Floor Spreading Evidence…

 Rocks close to mid-ocean ridge are very young  age of rocks continues to increase the further away from the ridge  Iron bearing minerals record Earth’s magnetic field reversing  these rocks show same field direction equal distance either side of the mid ocean ridge 8.9A

Continental Plates

Convergent Plate Boundary Sea Floor Spreading under another Subduction Zone 8.9B

Plate Tectonics

8.9B

Rift Valley

• long, deep valley bound by normal faults • forms where Earth’s crust being pulled apart • can appear on land or beneath bodies of water, where two plates are separating • on ocean floor between mid-ocean ridges, where new ocean crust is forming.

1. Explain the history leading up to the Theory of Plate Tectonics.

2. Describe how plate movements create crustal landforms.

Topographic Maps

• Show elevation • Uses contour lines • Can be used to identify landforms

Satellite View

Earth’s Rotation

 rotates (spins) on its axis  rotates counter clockwise  takes ~24 hrs per rotation  gives us day & night.

8.7A



Earth’s Revolution

orbits around the sun  takes 365.25 days  axis tilt and revolution causes seasons 8.7A

8.7B

The Moon

• Rotates on its axis once every 29.5 days • Revolves around the Earth once every 29.5 days • Therefore, we always see the same side of the moon • Moon revolves counterclockwise

Moon Phases

New Moon = no reflected light • We see the moon because it reflects light from the sun Full Moon = full circle of reflected light • phases caused by moon’s revolution around the Earth • phases are named for the lit portion of the moon 8.7B

•Waxing = getting lighter; Waning = getting darker • Crescent & Gibbous refer to the shape of the light being reflected

What Comes Next?

8.7B

1. What phase comes immediately after a full moon?

2. Which position would you find it?

Tides

• Caused by gravitational pull of Sun & Moon • Moon is much closer & has more influence • Spring Tides = higher high tides & lower low tides than average – Sun-Moon-Earth are aligned • Neap Tides = lower high tides & higher low tides than average – Sun-Earth-Moon at right angle 8.7C

8.8A

HR Diagram

1. Brightest star?

2. Hottest star?

3. Smallest star?

4. Name a … …red supergiant …white main sequence …white dwarf

8.8A

The Milky Way Galaxy

You are here.

• What units would you use to measure the distance from our Sun to the center of our galaxy?

8.8B, 8.8D

Universal Knowledge

1. Rotation causes _?_.

2. Seasons are caused by _?_.

3. Spring tides occur in what moon phases?

4. List the components of the universe from smallest to largest.

5. Name two things about stars that we can get from a Hertzsprung-Russel Diagram.

Reminders…

• Plate tectonics is the movement of crustal plates which alters landforms: formation of rift valleys, mountain building, and other landform changes • The moon goes through a cycle of changes both visually (phases) and forces acting on the Earth (tides) • The Universe is made of many parts including nebulae, stars, planets, and moons • Distance in the universe are measured in light-years.

»Any questions???