Mars Notes

1877: identified 79 canali, mistaken as man made canals

1894: wrongfully studied canals on mars

S195: Mariner 4, 6, 7 (flybys)

1971: Mariner 9 (orbiting)

1976: Twin Viking (landers)

• established harsh surface conditions and lack of liquid water

1997: Mars Global Surveyor, Pathfinder, rover Soujourner

2015: 5 orbiters, 3 rovers, one lander

Current: 5 orbiters, 2 rovers

CO2 similar to Venus

10,000 times thinner

little greenhouse effect

causes water to sublimate (solid to gas)

25 degree title

elliptical orbit

northern mars is drastic

winters cold enough to freeze the atmosphere (enlarge white cap)

Winds that cycle carbon dioxide gas cause large storms “dust-devils”

northern lowlands, southern highlands

southern hemisphere more cratered

Northern hemisphere, less cratered, newer crust

Early: Noachian - 3.7 billion years, more craters

Middle: Hesperian, 0.7 billion years, moderate craters

Recent: Amazonian, past 3 billion, light craters

Largest volcano in universe

26 km high

600 km across

result of magma plume

large canyon

4x deeper than Grand Canyon

Sedimentary walls similar to grand canyon

might offer fossils of martian life

orbital evidence: images of river beds

rover evidence: hydrated minerals of water based reactions

evidence of periodic heating events (impacts, volcanism)

Water ice

13x more water than earth removed by solar winds

dark streaks on crater walls implying salty water in summer

much warmer and wetter in past

atmospher 400x thinker than ours

global greenhouse effect

maybe global magnetic field protecting from solar wind stripping

enough pressure and heat for surface water

cool of core ends global magnetic field and decreases volcanism leading to today (no CO2 or water)

Carbon assimilation experiment:

• mixed soil with carbon dioxide and monoxide

• found no life

Gas exchange experiment:

• martian soil and “broth”

• found no life

Labeled release experiment:

• martion soil and radioactive “broth”

• showed signs of life (other missions debate)

Gas chromatograph experiment:

• measured no organic material in martian soil

methane varies with seasons, should diminish unless reproduced

three possibilities: comet impacts, geological activity, life

1. Layers carbonate grains similar to biological activity on Earth

2. PAHs produced by living and non-living processes

3. Crystals within meteorite match similar crystals from earth bacteria

4. images of rod-shaped structures resemble fossilized bacteria

1. non-biological mechanisms produce layered carbonates

2. PAHs produced by both living and non-living reactions

3. Similarities between crystals may be a coincidence

4. structures may be too small for RNA/DNA

Contamination

• can’t decontaminate humans

• worried about hurting ecosystems of earth and mars

release greenhouse gases to warm and increase pressure

would make habitable but not like earth

impractical