Mars: Earth’s little brother What are the similarities and differences you notice? ’s axis is tilted at 25 deg. What are on Mars like? Mars’s axis tilt changes dramatically. What happens when the tilt is less/more? Artist’s depiction of an ‘icy Mars’ Do the Earth and Mars have similar interiors? Why?

How do we even know what’s inside a ? : Are they similar? Why?


Nitrogen: 78% Doxide: 95.% : 21 % : 3% : 0.9% Argon: 2% : > 1% Oxygen: 0.1% Carbon Doxide: 0.002% Water: > 0.03% Is there ? Why or why not? Is there water on Mars? Why or why not?

Mars’s pole Is there water on Mars? Why or why not? Phase Diagram of Water

Earth Partial Pressure of Water PartialPressure Water of Mars

Temperature Is on Mars similar to that on Earth? Does this look like the Earth?

What kind of geologic processes can you see evidence for? Notice any big impact craters? : The biggest in the solar Olympus Mons: The biggest volcano in the

Is this similar to volcanoes on Earth? : The solar system’s biggest canyon

Our ‘grand’ canyon Mars or Earth? Mars or Earth?

Columbia Hills, Mars

Atacama , Chile , Mars Mars or Earth? Mars or Earth?

Kilauea Volcanoe, Hawaii Olympus Mons, Mars Mars or Earth? Mars or Earth?

Dubai, UAE Crater, Mars What is the evidence for past water on Mars? Mars or Earth? Mars or Earth?

Djado , Niger Valles Marineris, Mars Mars or Earth? Mars or Earth?

Holden Crater NE, Mars Delta, Argentina Mars or Earth? Yemen

Mars or Earth?

Mars Mars or Earth? Mars or Earth?

Niger Mars Seven minutes of terror

Curiosity descent

Google Mars

Mars: Take-away messages • Although smaller than Earth, Mars and Earth are similar in many ways. • Mars and Earth have similar interiors, although Mars has no liquid outer core, and so no magnetic . • Mars geology is/was formed by cratering, , tectonics and by AND WATER! • ( doesn’t seem to have been important) • Mars’s is different from Earth’s - lower , and full of CO2. • Mars’s small atmosphere and low makes liquid water unstable at its (at least right now). Percival ’s Mars Lowell’s Map of Mar published in 1895 Viking’s Mars 1976 Viking’s Mars 1976