Chapter #9 Possible fossil martian life in meteorites from Mars.


1. ALH84001 is one of how many meteorites found on Earth that are thought to have come from Mars? (page 142)

2. What type of meteorite is ALH84001, and where is it thought to have last been located before coming to Earth? (page 142)

3. Describe the isotopic evidence that suggests that ALH84001 (and the other martian meteorites) is a martian meteorite. (page 144)

4. What characteristics set ALH84001 apart from the other martian meteorites? (page 144)

5. Explain how the existence of mineral deposits made ALH84001 a strong candidate for a search for evidence of biological activity. (page 144 &endash; 145)

6. When is it believed that ALH84001 crystallized? (page 145)

7. Describe the event timeline of ALH84001 detailed in Figure 9.3. (page 145)

8. What quantitative measurements were used to determine the dates detailed in Figure 9.3? (page 146)

9. What were the five major areas identified by the original evidence provided by scientist at the 1996 press conference on ALH84001? (page 146)

10. Describe the precautionary steps (from the time it was collected to the actual testing of the meteorite) that were taken to ensure that ALH84001 was not contaminated. (page146 &endash; 147)

11. What is the argument given to suggest that 13000 years of time spent on the Antarctic ice sheet is not responsible for the features identified as evidence for biological activity in ALH84001? Page 147)

12. Describe the compositional layering and mineral grain evidence presented as support of biological activity in ALH84001. (page 147 &endash; 148)

13. Describe how PAHs were provided as evidence in support of biological activity in ALH84001. (page 148 &endash; 149)

14. Describe the intriguing fossil evidence for possible martian life? (page 151 &endash; 152)

15. Why does determining the temperature that the carbonate formations were deposited at help in the determination whether or not biological fossils from Mars exists in ALH84001? (page 152 &endash; 153)

16. How could the analysis of isotopes of carbon and oxygen help in determining the temperature of the carbonate formations of ALH84001? (page 154)

17. What does the analysis of magnetic minerals suggest about the temperature during the formation of carbonate deposits within ALH84001? What does the magnetic mineral analysis suggest about the martian magnetic field during the time of crystallization? (154 &endash; 155)

18. In what way do the ALH84001 bacterial fossils most distinctly differ from terrestrial bacteria? (page 156)

19. What is it about the size of the ALH84001 fossils them unlikely to be similar to the smallest living organisms on Earth? (page 156 - 157)

20. How does "Occam's Razor" provide support for the interpretation that biological origins are responsible for the evidence presented about ALH84001? (page 157 - 158)