Expect Venus to be
similar to Earth
(but it isn’t!)
Why does Venus have much more CO2 in atmosphere than Earth?
Surface Relief of Venus from Radar
Lots of Martian Science Fiction
Mars and the Pattern of
Geologic Activity
and Atmospheric Loss
Which planets can retain which gasses?
Ancient River
Channels?
(note channels older than some craters – by superposition)
Recent liquid water?
(water seeping out of underground “aquifer” ?)