Page:Illustrated Astronomy.pdf/48

 THE MOON

The Moon is primarily responsible for the Earth’s almost constant axis of rotation, preventing dramatic changes in the axial tilt. It is essential to mention that thanks to this obliquity of 23,5°, we experience the four seasons. Without it, we could experience times where we would receive sunlight only on one Earth side, producing an overheat, whereas the other half would freeze; or extreme seasons of both winter and summer in different locations.

Even though, as human beings, we have lived on this planet for thousands of years, yet there are many things we don’t understand completely. For example, though the Earth is almost a perfect sphere, slightly flatten on its poles, we still have to discover why the south pole is a little bit bulkier than the north pole.

Besides, Earth has different shapes on its surface. The largest mountain is Mount Everest, standing about 8,848 meters above sea level, located in Nepal. On the other side, the Mariana Trench, with a depth of 11,034 meters, which is the deepest trench in the world. In spite of these extreme examples, which seems to be so high or so deep for us, if we could compare Earth at a scale of a billiard ball, Earth would be much more even than the surface of a brand-new ball.



48 • • •