2.4. THE MOON

YouTube: National Geographic "Moon 101"

- MOVEMENTS OF THE MOON

The Moon moves into two different ways:

• ROTATION on its axis:
  It takes 28 days to complete one rotation.
• REVOLUTION around the Earth:
  It takes 28 days to complete one revolution. As a consequence, from the Earth, we see the same side of the Moon every day.

- LUNAR PHASES

YouTube: European Space Agency,ESA"Paxi and Our Moon: Phases and Eclipses"

The Moon is illuminated by the Sun from different angles. Its aspect varies due to rotation and revolution. There are eight phases that always occur in the same order. The following four phases are the most well-known:

New Moon The Sun illuminates the side of the Moon we don't see	First quarter We see the right half of the Moon illuminated.	Full Moon The Sun illuminates the side of the Moon we see.	Last quarter We see the left half of the Moon illuminated.

- TIDES

YouTube: Atomic School "Ocean's Tides Explained"

YouTube: MooMooMath and Science "Tides Explained-Spring and Neap Tides"

The Earth and the Moon attract each other due to the gravitational attraction. The effect of this force can be seen in the oceans:

• High tide: it occurs when the water level rises on the side of the Earth closest to the Moon and also on the opposite side.
• Low tide: it occurs in areas where the water level becomes lower.

- ECLIPSES

YouTube: National Geographic "Solar eclipse 101".

YouTube: National Geographic "Lunar eclipse 101".

It takes place when one celestial body totally or partially obscures another.

• A solar eclipse occurs when the Moon passes directly between the Earth and the Sun.

• A lunar eclipse occurs when the Moon passes through the shadow produced by the Earth.