Ch. 8 Flashcards
Rotation period of Mars
24 h 37 m
Atmospheric composition of Mars
95% CO2
Physical characteristics of Mars
Half the size of Earth, lower density world, temperatures well below freezing, little atmosphere, no oxygen, dry arid
Mars atmosphere
Thin but moderates temperature extremes
Mars orbit
more oblong than Earth’s a lot closer to the sun in summer than in winter
Mars seasons
Summer is short and warm and it’s winter long and cold
Ice caps
Winter ice caps much larger because carbon dioxide freezes out of the atmosphere, ice sublimes back into the atmosphere in summer
Environment
Lots of dust storms arise changing the surface appearance
Surface features
Smooth flat northern hemisphere and heavily cratered rugged southern hemisphere
Olympus Mons
The largest volcano in the Solar System is 600 km across and 26 km high
Mantle plumes
allow a continuous building of volcanic structures
Valles Marineris
Huge canyon at the equator of Mars formed by tectonic activity
Three eras of Mars
Noachian (oldest), hesperian (intermediate), amazonian (recent)
Water on mars
Once plentiful, visible riverbed and gulley formations, sedimentary rock structures
Mineralogical evidence
Hydrated materials found such as clay minerals, hydrated sulphates, hydrated silica and opal deposits
Martian rock
Cumberland
Evidence for contemporary flowing water
Dark, narrow streaks flowing downhill on Mars
Mars climate past
Significant out-gassing from volcanoes and the accumulation of Carbon dioxide
Climate change on Mars
As the planet cooled the magnetic field weakened and then disappeared, no ozone layer allows ultraviolet photodisintegration of water molecules
Mars tilt varies meaning?
That substantial seasonal changes occur more often, it tilt varies cause it does not have a moon
Three lines of evidence for life on Mars
Viking mission, methane, meteoritic evidence
Methane on Mars
Methane cannot survive for long periods in an atmosphere so there must be an ongoing supply
