1. Mars and Saturn II – What’s New?
For both planets, the textbooks are being rewritten, new developments this summer!

2. For Mars, the main scientific question is the existence of water in the remote past
Mars Explorations Rovers (“Spirit” and “Opportunity” are extensively studying two regions on the surface of Mars, both chosen for possibility of water

3. MER landing sites chosen to be places that seemed to be sites of water
“Spirit”: Gusev crater: crater with apparent ancient river flowing into it.
“Opportunity”: Meridiani Planum: site with signature of mineral hematite, mineral which forms in the presence of water on Earth

4. Spirit and Opportunity Landed in January
Both spacecraft still operating
Results to date
Spirit has found no evidence of ancient water on the surface (yet)
Opportunity has found conclusive evidence of ancient bodies of water at landing site

5. Opportunity landed in small crater with sedimentary rock deposits

6. Aquatic past of Opportunity landing site from detailed analysis of rock outcropping

7. Scientific Conclusions from Opportunity analysis
Landing site described as once being “soaking wet”
Deposits of hydrated sulfur salts
Presence of mineral jarosite (forms in presence of water on Earth)
Pockmarks in rocks believed due to mineral pockets dissolved…rocks were submerged
Ripple patterns in rocks indicating past lakes or oceans

8. All this strongly indicates (proves
All this strongly indicates (proves?) Opportunity landing site was submerged in water for a long period of time, long ago

9. Where is Opportunity now? At edge of Endurance Crater
If Opportunity goes in, it may not be able to come out

10. Spirit still functioning and searching
Spirit now less than half a mile from the “Columbia Hills”, best chance for sedimentary rocks

11. The next planetary adventure this summer: Cassini arrives at Saturn

12. One of the fascinating things about Saturn: its moon Titan
Interesting aspects of Titan: (1) 2nd largest moon in solar system, (2) only moon with a significant atmosphere

13. After a voyage of seven years, Cassini will fire its rockets and enter orbit around Saturn on July 1

14. Earth-based observations at infrared wavelengths reveal surface details on Titan
There may be a “hydrological cycle” based on methane and ethane on Titan

15. We’ll find out soon; the Huygens probe lands in January