Chapter 11

What is the reason that the northern plains of Mars have a much smaller crater density than the cratered terrain of the southern hemisphere?

The Earth is closest to the Sun in January, which is summer in the southern hemisphere. Why isn't the difference between northern and southern seasonal variations as extreme on the Earth as on Mars? (You should give an astronomical reason, which is part of the full explanation.

Suppose Mars had such a large orbital eccentricity that the north polar region was too warm in winter for carbon dioxide to condense as dry ice. What would the annual variation in atmospheric pressure be like in that case?

What is the reason that the Martian surface and sky are somewhat pink?

Mars has nearly the same rotation period as the Earth, yet Mars has no detectable global magnetic field. What possible difference between the two planets could account for the absence of a Martian magnetic field?

What may have caused the thick atmosphere that Mars is believed to have had in the distant past to have disappeared?

What evidence did the gas chromatograph-mass spectrometers on the \(V\) iking landers yield about the presence of life on Mars?