4. RUNNING WATER on Mars Runoff Channels - systems of interconnecting, twisting channels that merge into larger, wider channels. Resemble river systems on Earth. Completely dried up, no water is present today.

10. Outflow Channels - results of catastrophic flooding
Outflow Channels - results of catastrophic flooding. Only in the equatorial regions. Paths taken by large volumes of water draining from the southern highlands to the northern plains.

15. These floods probably also formed the “tear-drop” shaped islands found at the ends of the outflow channels.

22. The flow rate must have been as much as 100 times greater than the 105 tons per second carried by the Amazon River.

33. Another evidence for water is the presence of hematite in the form of iron-rich spheres. These spheres are found in the soil and naturally form in water.

36. Where is the water today
Where is the water today? May be locked in a permafrost layer under the soil’s surface, maybe a little more in the ice caps.

37. The best scenario is that the water originally formed runoff channels, then froze in permafrost. Volcanic activity melted the permafrost which carried flash floods and produced outflow channels.

38. The water then refroze and Mars remains dry to this day.

39. Viking I and Viking II tested for life on Mars with three tests: Gas Exchange Experiment - A nutrient broth was added to the soil and the device tested for gases that would be produced by metabolic activity.

40. Labeled Release Experiment - Compounds containing radioactive carbon were added to the soil. The device looked for products that would indicate that life had eaten or breathed the carbon.

41. Pyrolytic Release Experiment - Radioactively tagged CO2 was added to the soil and atmosphere. After a period of time, the gas was removed and the soil was tested to see if some CO2 had been absorbed.

42. It is essential that the space craft be sterilized before launch for these tests to be accurate.

43. Initially, all of the tests had positive results, but all the results could be explained by inorganic chemical reactions.