Moon and Mercury
1. The most accurate method for determining the distance to the Moon is by _Radar, light speed and distance measurement_. Page 196
2. Mercury can be seen only just after _dusk_ and just before _dawn__. Page 197
3. The radius of the Moon is about _1/4th_ that of Earth. The radius of Mercury is about _1/3rd_that of Earth. Page 198 and page 215
4. Because the Moon’s average density is so much lower than Earth’s average density, we can infer that the Moon must contain less _iron in its core_. Page 218
5. Mercury’s iron core contains a _much larger_ fraction of the planet’s total mass than does Earth’s core. Page 217
6. Mercury’s daytime temperature is higher than the Moon’s because it is proximity to the Sun_. Page 199
7. The _Maria_ on the Moon are dark, flat, roughly circular regions hundreds of kilometers in diameter. Page 199
8. Craters on the Moon and Mercury are primarily due to _Meteoric impacts_. Page 199
9. Mercury’s rotation was first measured using _doppler effect_. Page 203
10. Although Mercury’s daytime temperatures are always very hot, it may still be possible for it to have sheets of water ice at its _poles_. Page 206
11. The crater produced by the impact of a meteoroid on the Moon has a typical diameter about _10x_ times the diameter of the meteoroid. Page 207
12. The lunar crust is significantly _thicker_ than the Earth’s crust. Page 216
13. The lunar maria’s dark, dense rock originally was part of the lunar _mantle__. Page 219
14. Mercury’s _Magnetic field_ is about 1/100th that of Earth and was originally thought not to exist at all. Page 216
15. The most likely scenario for the formation of the Moon is a collision between Earth and a _Mar’s sized object, called “Theda”_. Page 218