New moon

The term new moon (Latin Interlunium ) refers to the naked eye can not be seen shining light ( Moon Phase ) of the Moon, if it is located between Earth and the Sun, that is, in conjunction with the Sun. Only after about 35 hours, the rightmost edge (left edge when observed from the southern hemisphere from ) illuminated by direct sunlight again. This moon phase is the Neulicht. The phase advance is called the new moon, because the moon is " renewed " in her apparently. The last visible phase before the new moon is called Altlicht.

Although the Earth -facing side of the moon always gets something reflected sunlight from the Earth ( earthshine ), but that will outshine in New Moon of scattered sunlight in the atmosphere so that the Moon with the naked eye can not be detected. In the night sky the moon is in principle not to see, because it is located along with the sun below the horizon.

A more precise temporal definition is:

" New Moon is the time at which the geocentric ecliptic longitude of the Moon and the geocentric ecliptic longitude of the sun are the same. "

This is called geocentric seen from a hypothetical observer at the center of the earth from. The definition is independent of the location of a real observer; New Moon takes place worldwide at the same time ( but different in different time zones corresponding local times ).

The astronomical symbol for new moon is a filled circle:

Special effects of the new moon

Solar eclipse

After about every six lunations of the moon when the sun seeming overtaking nearly zero for its ecliptic latitude. It happens in these cases, the line of nodes (intersection between the plane of the lunar orbit and the ecliptic plane ) in moments in which these covers approximately with the line connecting the centers of the Earth and the Sun. This applies to both the new moon as well as the full Moon. In new moon thus a sun, under a full moon a lunar eclipse takes place.

Riptide

A spring tide occurs both at new moon and at full moon. Among the most part by the Moon ( or from the circular motion of both around the common center of gravity) derived, acting on the earth tide forces ( mainly attraction on the moon -facing side, predominantly centrifugal forces opposite) are derived from the sun, tidal forces adds both when the moon is in stands for sun conjunction and in opposition. In such cases, the tide is higher than average. Make Moon and Sun as seen from Earth from a right angle ( to waxing and waning crescent ), the flood is the smallest and is called neap tides.

The moon age

The time in days that has elapsed since the last new moon, is commonly referred to as the moon age. At full moon, the moon's age is 15 days. In the Easter calculation, the age of the moon on the last day of the previous year plays a role and is called epact.