Unit 2: The Earth in Space

1. Unit 2: The Earth in Space Mr. Ross Brown Brooklyn School for Law and Technology

2. Aim: How is our Earth composed? • Date: 16 Sept 2016 Do now: This question may require the use of the Earth Science Reference Tables. The Earth's shape most closely resembles which of the following object: • a basketball • a pear • a ping-pong ball • an apple

3. And another, just for fun! This question may require the use of the Earth Science Reference Tables.According to the Earth Science Reference Tables, the equatorial radius of the Earth is approximately: • 637 km • 6370 km • 63700 km • 637000 km

4. The Earth in Space Taken December 7, 1972, by the crew of the Apollo 17 spacecraft, at a distance of about 45,000 kilometers (28,000 miles). (source: Wikipedia)

5. In this unit we will learn: • The characteristics of Earth’s 3 major zones • How seismic waves provide insight into Earth’s interior • What the magnetosphere is • How the Earth’s gravitational pull is created

6. What are Earth’s Interior layers? • 19 Sept 2016 • Do now: Compare the mass of the crust to the mass of the mantle to the mass of the core. Use fractions or percentages. For example, the crust represents _____% of the mass of the earth, the mantle is _____%, and the core is ______%.

7. What are Earth’s Interior layers? • Can’t see inside Earth, but scientists have “seen” with seismic waves, vibrations • Caused by earthquakes or explosions • Earth has layers, or zones • Crust: thin, solid, outermost layer • 1% of earth’s mass • Mass: the amount of matter in an object • Oceanic Crust: 5km-10km thick • Continental Crust: 15km-80km thick

8. What are Earth’s Interior layers? • Mantle: • 2/3 of the earth’s mass • 2,900km thick • Upper mantle is cool and brittle (lithosphere) • Due to heat and pressure, next layer of rock flows • Asthenosphere exhibits plasticity (solid that can flow) • Core • Center of the earth, composed mostly of iron • Outer core is dense liquid layer • Inner core is very dense and solid

9. Earth’s Interior layers

10. Inferred Properties of Earth’s Interior

11. Aim: How do we draw inferences about the composition of the earth? • 20 Sept 2016 • Do now: This question may require the use of the Earth Science Reference Tables.The true shape of the Earth is best described as a: • perfect sphere • perfect ellipse • slightly oblate sphere • highly eccentric ellipse

12. Aim: How do we draw inferences about the composition of the earth? This question may require the use of the Earth Science Reference Tables.At which location would an observer find the greatest force due to the Earth's gravity? • North Pole • New York State • Tropic of Cancer (23.5N) • Equator

13. Seismic Wave Studies • Two types of seismic waves • P waves (primary) travel through liquids, solids, and gases. Faster than S waves. • S waves (secondary) travel only through solids. • Core blocks seismic waves in shadow zones

14. How does Gravity affect objects on the Earth? • Gravity: the force of attraction that exists between all matter in the universe

15. Newton’s Law of Gravitation • The force of attraction between any two objects depends on their masses and the distance between them. • Mass is the amount of matter in an object. • Weight is an object’s mass and distance from center of the earth.

16. Newton’s Universal Law of Gravitation states that any two bodies in the universe attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

17. How does the earth move in space? • 22 Sept 2016 (my sister’s birthday) • Do now: This question may require the use of the Earth Science Reference Tables.The length of an Earth day is determined by the time required for approximately one: • Earth rotation • Earth revolution • Sun rotation • Sun revolution

18. How does the earth move in space? • 22 Sept 2016 (my sister’s birthday) • Do now: The autumnal equinox occurs today at 10:21 AM. What does this mean? Why does this happen?

19. How does the earth move in space? • Rotation: spinning on an axis. Each rotation is about 24 hours (one day) • Revolution: each revolution takes about 365 days (one year)

20. How does the earth move in space? • Earth’s revolution around the sun is slightly elliptical, not quite a circle. • Closest to the sun at perihelion, farthest from the sun at aphelion.

21. How does the earth move in space? • Earth’s orbit lies in a plane but earth’s axis is 23.5° from perpendicular to the plane. • As earth revolves around the sun, this tilt produces our seasons.

22. How does the earth move in space? • Solstice: the Sun stops, or the days stop lengthening or shortening • Equinox: equal length of day and night

23. Thought Question • What causes our winter in the Northern Hemisphere?

24. How do we keep track of time on our earth? • 23 Sept 2016 Do now: Base your answers to questions 15 and 16 on the United States time zone map shown below. The dashed lines represent meridians (lines of longitude). 15) If the time in Buffalo, New York, is 5 a.m., what time would it be in San Francisco, California? • 8 a.m. • 2 a.m. • 3 a.m. • 4 a.m.

25. How do we keep track of time on our earth? • 23 Sept 2016 Do now: Base your answers to questions 15 and 16 on the United States time zone map shown below. The dashed lines represent meridians (lines of longitude). 16) The basis for the time difference between adjoining time zones is Earth’s • 1° per hour rate of revolution • 1° per hour rate of rotation • 15° per hour rate of revolution • 15° per hour rate of rotation

26. How do we keep track of time on our earth? • The earth is (roughly) a sphere • Circumference=360° • Every 15° is an hour, 24 hours in a day • How many time zones are there around the world? • International Date Line is where the next day begins

27. World Time Zones

28. How does the US account for regional time differences? • Daylight Saving Time • Goal is more sunlight hours for more work in the summer

29. How do we keep track of activity across the earth? • Satellites: Any objects in orbit around other body with a larger mass. • Uses: meteorology, communications, navigation, science, military, government • Orbits: geosynchronous, polar

30. Satellite Images

31. How can we keep track of our location on the Earth? • 26 Sept 2016 • Do now: This question may require the use of the Earth Science Reference Tables. How are latitude and longitude lines drawn on a globe of Earth? • Latitude lines are parallel and longitude lines meet at the poles. • Latitude lines are parallel and longitude lines meet at the equator. • Longitude lines are parallel and latitude lines meet at the poles. • Longitude lines are parallel and latitude lines meet at the equator.

32. How can we keep track of our location on the Earth? • Earth is a sphere • Rotates on an axis, which runs through the geographic poles • Split by an equator (separates north & south hemispheres (half-spheres))

33. How can we keep track of our location on the Earth? • Parallels tell us how far north and south of poles we are • Distance north or south is latitude, measured in degrees. Equator is zero, poles are 90° • Brooklyn is about 40.5°N

34. How can we keep track of our location on the Earth? • East and west are measured in meridians • Half-circles running from pole to pole • Longitude is distance of meridian, in degrees • Brooklyn is about 74°W

37. How do maps represent actual features of the earth? • 27 Sept 2016 • Do now: This question may require the use of the Earth Science Reference Tables. An airplane takes off from a location at 17°S latitude and flies to a new location 55° due north of its starting point. What latitude has the plane reached? • 28°N • 38°N • 55°N • 72°N

38. This question may require the use of the Earth Science Reference Tables. Base your answer to this question on the topographic map below. Points X, Y, and Z are locations on the map. Elevations are expressed in meters. Which profile best represents the topography along the dashed line from point X to point Y?

39. How do maps represent actual features of the earth? • Cylindrical Projection: most common, often referred to as Mercator Projection. • Accurate near equator, but distorted closer to poles.

40. How do maps represent actual features of the earth? • Conic Projection: imagine a cone lined with mirror placed over the earth • Accurate in middle of cone, rather badly distorted as we move out.

41. How do maps represent actual features of the earth? • Interrupted Projection: In order to focus on landmasses, and to flatten the spherical shape, omits large spaces, such as oceans.

42. How can we fully use the information in the Earth Science Reference Tables? • 28 Sept 2016 • Do now: Please write your name on your copy of the ESRT. Take these first few moments and leaf through your copy. • Become familiar with the different sections and how each relates to the various parts of our earth science curriculum.

43. What protects the Earth from solar radiation? • 14 October 2015 • Do now: What causes the Aurora Borealis?

44. What is the Magnetosphere? NO!

45. What is the Magnetosphere? • The region in space around our Earth where charged particles are controlled by the planet’s magnetic field • Protects us from solar radiation