Full moon

Full moon ( astronomical symbol: ) is the time at which the sun and moon are in opposition to each other, ie seen from Earth in opposite directions. The moon is in this case usually slightly above or below the plane of Earth's orbit ( the ecliptic ). If it is at this time exactly equal to the ecliptic, an eclipse occurs.

The contrast to a full moon is a new moon, when the moon passes between the Sun and Earth is. In this case, it may be a solar eclipse.

Properties

A more precise definition is: Full Moon is the time at which the ecliptic geocentric longitude of the moon is greater than the 180 ° ecliptic geocentric longitude of the sun.

This is called geocentric seen from a hypothetical observer at the center of the earth from. The moon is full, therefore the world at the same time instead ( but different in different time zones corresponds times ). When observed from the surface of time and the sight of the full moon in a small, imperceptible extent on the location of the real observer dependent.

At full moon, the moon reaches its maximum brightness and has an apparent magnitude of about -12.5 to -13 mag. Compared to the light of the full moon the sun is about 400,000 times as bright; in comparison with the light of a starry night sky, the full moon is about 250 times as bright, the brightness of the full moon varies due to the elliptical orbits of the Earth and Moon. Is the earth the sun particularly close ( perihelion ) and at the same time the moon at its perigee ( perigee ), the full moon is about 22 percent brighter than in the reverse case, when both distances are maximal. In September 2006 and in March 2010, the full moon was very close to perigee, such situations occur only once every nine years. The moon culminates on the day of the full moon each to midnight. At this time the sun passes through the lowest point of its path in the sky.