1. Earth in Space Heather Frazier

2. Big Bang Theory The Big Bang is a theory that explains how the universe expanded from a single point. The Big Bang occurred 13.7 billion years ago. All the matter, energy, and light; were all compacted into an infinitely dense point. The universe then expanded tremendously.

3. Where is earth located In the universe In the universe Milky way galaxy Milky way galaxy On Orion’s Arm On Orion’s Arm 3 rd planet from the sun 3 rd planet from the sun

4. What causes Night and Day Earth rotates on its axis, one full rotation takes 24 hours. As the Earth rotates different sides are exposed to the sun causing Night and Day Earth rotates on its axis, one full rotation takes 24 hours. As the Earth rotates different sides are exposed to the sun causing Night and Day

5. Seasons on Earth http://www.youtube.com/watch?v=Pgq0LT hW7QA http://www.youtube.com/watch?v=Pgq0LT hW7QA http://www.youtube.com/watch?v=Pgq0LT hW7QA http://www.youtube.com/watch?v=Pgq0LT hW7QA The tilt of Earth is responsible for causing seasons As the earth moves through its elliptical orbit the density of the sun’s rays change creating seasons

6. Why are days longer in the summer? During summer in the N. Hemisphere the Earth’s rotation on the axis has the sun’s rays concentrated over the tropic of cancer. This creates summer and over 12 hours of sunlight. During summer in the N. Hemisphere the Earth’s rotation on the axis has the sun’s rays concentrated over the tropic of cancer. This creates summer and over 12 hours of sunlight. When the rotation due to the tilt of Earth has the Sun’s rays concentrated over the Tropic of Capricorn we experience winter When the rotation due to the tilt of Earth has the Sun’s rays concentrated over the Tropic of Capricorn we experience winter

7. precession Precession is the change in orientation of the rotational axis of a rotating body Precession is the change in orientation of the rotational axis of a rotating body Meaning there is a change in the direction of the axis, but without any change in tilt. Meaning there is a change in the direction of the axis, but without any change in tilt. This changes the stars that are near or not near the poles. This changes the stars that are near or not near the poles. Polaris which is currently the North Star has moved closer to the poles and the star Vega will soon be the “north star” Polaris which is currently the North Star has moved closer to the poles and the star Vega will soon be the “north star”

8. Nutation Nutation refers to the rocking or swaying motion as the Earth moves on it’s axis Nutation refers to the rocking or swaying motion as the Earth moves on it’s axis This changes the angle of the axis by a half degree either way over an 18 year period and is due exclusively to the moon This changes the angle of the axis by a half degree either way over an 18 year period and is due exclusively to the moon http://phet.colorado.edu?en?simulation/gra vity-and-orbits http://phet.colorado.edu?en?simulation/gra vity-and-orbits http://phet.colorado.edu?en?simulation/gra vity-and-orbits http://phet.colorado.edu?en?simulation/gra vity-and-orbits

9. Barycenter This is the point between 2 objects where they balance each other. This is the point between 2 objects where they balance each other. It is the center mass where two or more celestial bodies orbit each other. It is the center mass where two or more celestial bodies orbit each other. The sun although the center of the universe is not stationary, it moves as other planet’s gravity “tug” on it. But it never strays too far from the solar systems barycenter. The sun although the center of the universe is not stationary, it moves as other planet’s gravity “tug” on it. But it never strays too far from the solar systems barycenter.