Red Planet Mars

Time to think……

When can you observe Mars?

a) sunrise

b) noon

c) sunset

d) midnight

Northern Lowlands

Southern Highlands

Theories of Dichotomy

• Large impact on northern hemisphere– Problem: edges not very smooth

• Plate tectonic activity– Northern hemisphere was an expanding ocean

• Analogous to Atlantic Ocean on Earth

Olympus Mons, Largest volcano in solar system.

Time to think……

Work out ‘Exercise I. Martian Features’

in class activity ‘Mars’.

Runaway Icehouse Effect

Time to think……

Work out ‘Exercise II. Martian Atmosphere’ in class activity ‘Mars’.

Number of dust devils is largest in summer.

CO2 snow in winter.

Seasons in hemispheres differ

• Due to elliptical orbit• Summer in southern hemisphere occurs at

perihelion, at aphelion in northern hemisphere– Atmospheric pressure drops during southern

hemisphere’s winter

• At midsummer, southern hemisphere’s ~150 K, while the northern hemisphere’s ~200 K

P = 7 h 39 mTakes ~3 days to set after rising

Time to think……

Recall Phobos orbits Mars in about 7 hours, Deimos orbits slightly slower than geosynchronous orbit and a Martian day is 24 h 37 m. Which of the following will eventually occur?a) Phobos will eventually fly away b) Phobos will keep getting closer and closer to

Marsc) Phobos will be struck by Deimosd) Nothing, Phobos will remain in its present orbit

forever