1. Test Review Terms Elliptical orbit Rotation Axis Full moon Aphelion Major axis Foci Semimajor axis Perihelion Sun Maunder minimum Solar day Seasons Lunar phases photosphere Fission Fusion Electromagnetic radiation Ecliptic Vernal equinox Solar eclipse Lunar eclipse Summer solstice Autumnal equinox Winter solstice Keplar’s laws Law of universal gravitation precession

2. sun occupies one focus of the ellipse, not the center. The other focus is empty. An ellipse is “almost” a circle, so the universe is geometric although not perfect. The formula used to determine the shape of the ellipse is e=d/l where eccentricity is equal to the distance between the foci divided by the length of the major axis Keplers 1 st Law – law of Ellipses

3. Spring day characterized by day and night of equal lengths Vernal equinox

4. Plane of the Earth’s orbit about the sun ecliptic

5. equation that validates his second law. equation that validates his second law. P 2 = a 3 Keplers 3 rd Law

6. Earth’s position around December 21st, at which the northern hemisphere has its minimum daylight hours Winter solstice

7. Periods of low sunspot activity Maunder minimum

8. Imaginary line through which the Earth rotates on axis

9. Phase of the moon in which it appears entirely illuminated Full moon

10. point that determines the shape of ellipse foci

11. Half the distance of the major axis Semi major axis

12. Occurs when the moon passes directly between the sun and earth Solar eclipse

13. The statement that describes the relationship among the masses of two bodies and the distance between them Law of universal gravitation

14. Wobble of the Earth’s axis caused by the Moon’s gravitational force on Earth precession

15. Star closest to our planet sun

16. Caused by the tilt of the Earth and its orbit around the sun seasons

17. Passes through the foci of an ellipse Major axis

18. An imaginary line between the Sun and a planet that sweeps out equal amounts of area in equal amounts of time Kepler’s Second Law

19. Point in Earth’s revolution around the sun at which it is furthest aphelion

20. Electric and magnetic disturbances that travel through space Electromagnetic radiation

21. 24 hours, our time keeping system is based on it. Solar day

22. Occurs when the moon passes through the earths shadow Lunar eclipse

23. Orbit that is less than one but greater than 0 in eccentricity Elliptical orbit

24. Earth’s position around June 21, at which the northern hemisphere has its maximum daylight hours Summer solstice

25. Point in the Earth’s orbit when closest to the sun perihelion

26. Sequential changes in the appearance of the moon Lunar phases

27. Earth spining on its axis in a 24 hour cycle rotation

28. High energy required, fusing of 2 or more lighter atoms into a larger 1, produces radiant energy of stars, hydrogen bomb fusion

29. Splitting of a large atom into two or more smaller ones, takes little energy, produces many highly radioactive particles, atomic bomb fission

30. Emits most of the light from the sun photosphere

31. Fall day characterized by day and night of equal lengths Autumnal equinox