IMPACT CRATERS!

They say that my surface is marked by impact craters! It sure is! These impact craters form when asteroids and comets collide into me! Ouch*
There are about half a million craters on me with diameters greater than 1 km!

Since impact craters accumulate at a nearly constant rate, the number of craters per unit area superposed on a geologic unit can be used to estimate my age. Because there isn't much of an atmosphere around me, or weather... recent geological processes ensure that many of the craters on me have remained relatively well preserved in comparison to those on Earth.

My largest crater, which is known to be the largest crater in the Solar System, is called the 'South Pole-Aitken basin'. It is on my far side between the South Pole and equator and is 2,240 km in diameter and 13 km in depth!!

Maria, Maria....

Let me tell you about Maria...
she definitely doesn't give me the shine that the Sun does, but she is an important feature of myself that you must know about!

The dark and relatively featureless lunar plans which can clearly be seen with your naked eye are called maria (singular mare), Latin for seas, since they were believe by ancient astronomers to be filled with water! pfft...

These are now know to be vast solidified pools of ancient basaltic lava. The majority of these lavas erupted of flowed with impact basics that formed by the collisions of meteors and comets with the lunar surface, Maria are found almost exclusively on the near side me, with the far side having only a few scattered patches covering about 2% of my surface, compared with about 31% on my near side.
The most likely explanation for this difference is related to a higher concentration of heat-producing elements on the near-side hemisphere, as has been demonstrated by geochemical maps obtained from the Lunar Prospector gamma-ray spectrometer, such a long name!
Several provinces containing shield volcanoes and volcanic domes are found within the near side maria.


This song was NOT created after the maria on my surface....

http://www.youtube.com/watch?v=6Ml3NUIDpFg