1. The Earth

2. 1) Isaac Newton developed a theory of gravity that helped to explain why the planets orbit the Sun and moons orbit planets.

3. How did the Earth form?
7) One theory about how the Earth formed states that while solar gas and dust (a nebula) were swirling around and slowly condensing to form the Sun, a small part of the nebula escaped the Sun’s gravity and became trapped in an orbit around the Sun.

4. Earth
6) Earth is the largest rocky planet.

5. What is a rotation?
8) Earth spinning on its axis
24 hours

6. What if Earth rotated faster?
The days would become shorter!

7. What if Earth rotated slower?
The days would become longer!

8. Earth vs. Sun
3) The Earth is 93,000,000 miles away from the Sun.

9. What unit of distance do we use to measure objects in our solar system?
2) AU is Astronomical units – the average distance between the Earth and the Sun.
3) How we measure with in our solar system.

10. 4) Light travels at 186,000 miles per second and it takes 8
4) Light travels at 186,000 miles per second and it takes 8.3 minutes for light to travel from the Sun to Earth. 5) We measure distances outside our solar system in light years.

11. What is revolution? 9) Revolution is orbiting around another body.
Earth revolves the sun.
11) 365 days

12. What would happen if the Earth revolved slower?
The year on the Earth would be longer.

13. What would happen if the Earth revolved faster?
The year on the Earth would be shorter.

14. Why does Earth have leap year every 4 years?
12) There are (or 6 hours) days in a year.
13)Every four years the .25 part or 6 hours of a day adds up to one day that must be added to the calendar to keep it accurate.

15. The Tides

16. The Tides

17. The Tides
14)The gravitational pull of the Moon, and to a lesser degree the Sun, interacts with the rotation of the Earth and the shape of ocean basins to produce the tides.

18. The Tides
15)The gravitational pull from the moon, and the spinning of the earth, causes ocean water to bulge, producing the tides.

19. The Tides
16) A synodic period is also known as the time it takes for the moon to change from one high tide to another high tide.