Test question 9.1

1. Test question 9.1 • Mercury’s spin is in a 3:2 resonance with its orbit. It means that • vMercury’syear last 1.5 Mercury days • xMercuryhas a sideway spin • xMercury’sorbit is highly elliptical and inclined • xMercury’smoon goes around it 3 times a year.

2. Test question 9.2 • We probe the surface tomagraphy of Venus with radars because • xVenussurface is rapidly changing as a consequence of volcanic activities. • xWecan directly detect the sound of volcanic eruption on Venus • xEchomapping is more accurate than imaging • vSurfaceof Venus cannot be directly observed and imaged through its thick atmosphere

3. Test question 9.3 • Very low crater density and many active volcano on the surface of Venus indicate: • vVenushas a molten interior and active surface tectonic • xVenus’ atmosphere is very erosive • xVenushas a strong magnetic field • xVenusformed much later than the Earth

4. Test question 9.4 • Mount Olympus on Mars is the largest and highest volcano in the solar system. It is able to dwarf volcano on Earth because • xVolcanisactivities were much more intense on Mars than on Earth • xMarshas much smaller moons than the Earth • vGravityof Mars is smaller • vTheinterior of Mars is frozen solid

5. Test question 9.5 • The northern plane on Mars has much fewer craters than Mars’ southern hemisphere because • xThereis a gravity anomaly in Mars’ southern hemisphere • vMarsnorthern hemisphere was flooded and resurfaced by volcanic lava after the formation of most impact craters. • xMarshas a strong asymmetric magnetic field • xMarswas impacted by another planet with similar mass.