The best way to find the exact distance to the Moon is to:
bounce lasers off the retroreflectors left on the surface by the Apollo landings.
What is the reason that it is so difficult to view Mercury from Earth?
Mercury is always very close to the Sun.
The orbit of Mercury is more elliptical than that of any other terrestrial planet.
Mercury experiences extreme high and low temperatures between night and day because:
it has no atmosphere to moderate temperatures over the globe.
Comparing the densities of the Moon and Mercury, we find:
the Moon's is similar to Earth's crust, while Mercury's is similar to the entire Earth.
The lunar mare are found:
almost entirely on Earth side, where the crust was thinner.
The lunar highlands are:
more rugged, heavily cratered , and older than the lunar mare.
The youngest features visible with telescopes on the Moon are:
the craters sitting atop the mare.
What is true of the Moon's orbital and rotational periods?
They are equal.
The chief erosive agent now on the Moon is:
the rain of micrometeorites chewing up the regolith.
The rate of cratering in the lunar highlands shows us that
they range from 4.6 - 4.4 billion years old, on average.
The average rate of erosion on the Moon is far less than on Earth because
the Moon lacks wind, water and an atmosphere.
Which type of feature is the best evidence of lunar volcanism?
rilles associated with lava flows accompanying the mare formation
Almost all we know about Mercury has come from:
the three flybys of Mariner 10.
The scarps on Mercury were probably caused by
the interior cooling and shrinking.
The presence of a Mercurian magnetic field surprised the planetary scientists on the Mariner 10 team because
the dynamo theory predicted that Mercury was spinning too slowly for one.
Which of these theories seems to best explain the Moon's origin?
What are the major factors that rule out the co-formation theory for the Moon-Earth system?
Each body has a different density and a different chemical composition.
The cratering of the lunar highlands shows us:
they are older than the smoother maria.
Ice has been detected near the poles of both the Moon and Mercury.