1. Earth’s relative motion

2. 1. Kepler’s 1 st law states that planetary orbits are _________________ shapes? 2. Kepler’s 2 nd law states that 2 equal intervals of time an imaginary line connecting a planet and the sun will sweep an equal amount of ___________? 3. Kepler’s third law states that the innermost planets orbit ______________________ than the outermost planets. 4. Rotation is the earth spinning on it’s _________________. 5. One trip around the ______________ is called a revolution.

3.  EEn.1.1 Explain the Earth’s role as a body in space.  EEn.1.1.1 Explain the Earth’s motion through space, including precession, nutation, the barycenter, and its path about the galaxy. Explain relative motion of the Earth in the solar system, the solar system in the galaxy, and the galaxy in the universe—including the expanding nature of the universe; Orbital motion (Earth around the Sun- once/year, seasons depend upon an approximate 23.5 degree tilt); Rotation around our axis (day/night,)

4.  How do galaxies and planets move in the universe?

5.  Rotation  Turning or spinning of a body on its axis  Revolution  Motion of a body along a path around some point in space  Precession  Slight movement of Earth’s axis 26,000 years

6.  Results in day and night  24 hours  1,667 km/hr (1,036 mi/hr) Prove Earth is Rotating? OK!

7.  Earth moves around the sun in an elliptical orbit  Speeds around 107,000 km/hr (66,500 mph)  Average distance is 150 million kilometers  Perihelion is the point where earth is closest to the sun  Aphelion is the point where earth is farthest from the sun

8.  Earth’s axis is tilted about 23.5º on its axis  This tilt brings the sun 23.5º south of the equator on the winter solstace  This tilt bring the sun 23.5º north of the equator on the summer solstace Earth's Seasons

9.  Direction which earth’s axis points changes very slowly over time without a change in tilt  Takes about 26,000 years to complete one period  Currently the axis points toward Polaris making it the North Star, in 14,000 years Vega will be the North Star. Precession and polar shift

10.  Earth accompanies the sun as the entire solar system speeds toward a distant star, Vega  The sun revolves around the galaxy  Over 230 million years  At 250 km/sec  Now Earth is approaching our nearest galactic neighbor, Andromeda Earth's not orbiting the sun?!

11.  Earth’s only natural satellite  Orbit’s Earth in one month  When viewed from the North Pole, the orbit is counterclockwise  Average distance is 384,401 kilometers  Point close to the Earth is Perigee  Point farthest from Earth is Apogee

12.  Phases are the amount of moon that appears lit  Half of the moon is always illuminated  Phases result from the motion of the moon and the sunlight reflected from its surface  Every 29.5 days Moon Phases supermoon

13.  Daily elevation changes of the ocean surface.  Rhythmic  Caused by gravitational pull of the moon  Atmosphere and ocean are fluids and free to move due to this force.  The sun is further away resulting in less tug tidal mystery bay of fundy

14.  The moon pulls on Earth and Earth pulls on the moon  This pull causes the Earth to wobble on its axis by about ½ a degree.  Changing in the tilt of the Earth’s axis  How does this differ from precession? gyroscope demo

15.  Point between 2 or more objects where they balance each other  Point where 2 celestial bodies orbit each other barycenter barycenter animation

16.  When a moon orbits a planet or a planet orbits a star, both are actually orbiting a point outside the center of the larger body.  The moon and earth actually orbit a spot about 1,710 km below earth’s surface.

18.  Not a true sphere  Called an oblate spheroid, geoid, or ellipsoid

19.  Not equal throughout  Poles are squished making a bulge at the equator  Diameter and circumference are greater at the equator than at the poles.

20.  Earth’s rotation and gravity  Gravity pulls on the mass causing it to contract  Rotation causes earth to flatten due to centrifugal force  The force that causes objects to move outward, away from the center of gravity  We call this the coriolis effect coriolis effect

21.  Topography- study of surface shape and feature  On a global scale this difference is very small  Mt. Everest is about 8,850 m above sea level  The Mariana Trench is about 10,900 m below sea level  The difference is only about 19,000 m or 12 mi