Ch. 13
Applying the Concepts

<See the back of the chapter.>

Questions for Thought
 
2. 	The existence of dry channels and tributaries point to the abundance of water at some earlier time.

The source of water was vulcanism but Mars today is geologically dead. Water does not stay around on Mars because the H20 molecule is much lighter than the CO2 molecule. Mars is not very massive so lighter molecules escape.

5. 	Similarities: Both are mostly helium and hydrogen. Both give off more radiation than they absorb.

Differences: The Sun is much, much more massive. The Sun is much, much hotter. Nuclear fusion occurs in the Sun.

7. 	Life! The rise of anaerobic life forms that convert CO2 to O2.

9. 	Shooting stars are meteors that are burning up upon entering the Earth’s atmosphere. They are remnants of comets that have broken up. If they make it to the earth’s surface they are called meteorites. Meteors will continue to orbit the Sun along the same path as the erstwhile comet did.

<Attached Questions>

 Ceres has a period of 4.7 years.

 rG3/T2 for Solar A and Chandra is 1.311×1011 km3/hr2 or close to it.

 383,000 km to the Moon.

 1. T	11. d
 2. T	12. b
 3. T	13. c
 4. F	14. c
 5. T	15. d
 6. F	16. d
 7. T	17. b
 8. T	18. c
 9. F	19. c
10. T	20. a
		21. c
		22. d
		23. b
		24. a
		25. d