Pa Driving Permit Free Quiz

6

This well-known face of the Moon , photographed by the Clementine spacecraft.

has enormous number of craters, dark areas (seas and oceans) and bright (continents or highlands).

Below, the image is known as dark side which, without the existence of the spacecraft would not know what it is.

Look at the two pictures: Notice the difference?

visible side contains most of the seas (32% of the surface), while it has almost nothing hidden (8%).

Why?


response would be useful first to read something about the origin of the seas .

see, the moon was at its formation a thin crust of very dense material, called anorthosite, which is light in color, and gives coloration to our satellite.

anorthosite brought from the Moon during the Apollo missions. Below

anorthosite layer, was a sea of \u200b\u200bmolten basalt darker, and higher density. (In the diagram below is the mantle)

For some reason, still not very clear, anorthosite crust was thinner on the near side (60 km) than in the invisible (over 100 km).

As the seas are formed by asteroid collision, which fell on the near side came more easily to cross the cortex, while those of the dark side did not. Thus, it is this difference between the two sides moles.

Why the difference in thickness?

There are several theories to explain this difference. Some argue that the origin of the Moon , which according to most accepted idea was due to collision with a body diameter of the planet Mars, the Moon was to arise the difference of course, augmented by terrestrial attraction.

Others think that the attraction of Earth tides in the fluid was Luna, which ended in making the crust is so different in thickness.

Certainly the latter is the most accepted hypothesis, but there are still things to be resolved, they are not so easily explained.

topographic map with data from the Clementine spacecraft. The blue colors of violets are low-lying areas (Note that the seas are in that color.) The highlands are light colored or reddish. In the image on the right below the area of \u200b\u200bAitken, violet.

What is wrong with the theory of the thickness of the crust?

The simple explanation that the difference between the two sides in terms of quantity lunar seas is due to the thickness of the crust, has its drawbacks, since for example there is an area in the region not visible (you can enlarge the map and up in the face not visible, purple) which is very low, implying a thinner crust, and yet contains no Tues

His name is South Pole-Aitken basin (South Pole Aitken basin), and some believe it is the biggest impact zone of the solar system, with nearly 2500 km in diameter and more than 12 km. deep.

Despite being on the face not visible, in certain circumstances the edge of this region can be seen in the southern limb of the Moon from Earth. It is called Montes Leibnitz.

"Small" irregularities seen in the lunar edge are the Montes Leibnitz.