Solar system

Phases of the Moon and eclipses

Phases of the Moon and eclipses

The movement of the Moon in its orbit around the Earth causes the Sun to illuminate it differently, depending on the position. This causes the moon phases and, if the three stars are in a straight line, the eclipses.

The phases of the Moon determined, since ancient times, the measure of time, while the eclipses were taken as spectacular, magical and transcendent events.

The phases of the moon

Since the Moon revolves around the Earth (it is its only satellite), sunlight reaches it from different positions, which are repeated at each turn. When it illuminates the entire face we see, it is called a full moon. When we do not see it in the sky it is the phase of the new moon. Between these two phases you only see a piece of the moon, a growing room or a waning room.

The first civilizations already measured the time counting the moon phases. Each phase lasts a week. A month is approximately the duration of the entire lunar cycle or lunation.

Eclipse of the Sun, eclipse of the Moon

Sometimes, the Sun, the Moon and the Earth are located forming a straight line. Then shadows occur, so that the Earth falls on the Moon or vice versa. Are the eclipses.

When the Moon passes behind and is placed in the shadow of the Earth, a Lunar Eclipse is produced (drawing, left). When the Moon passes between Earth and the Sun, it covers it and a Solar Eclipse is produced (drawing, right).

If a star comes to completely hide the other, the eclipse is total, if not, it is partial. Sometimes the Moon sets before the Sun, but only hides the center. So the eclipse has an annular, ring shape.

Discover more:
• The phases of the Moon, in detail

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