A new moon is the opposite bookend of a full moon. The Moon passes between the Earth and the Sun, and the half the Sun lights is turned away from us. From the ground there is almost nothing to see. The Moon rises and sets with the Sun, lost in its glare, and for a night or two the sky after dark holds no Moon at all. People notice the full moon and overlook the new one, but it arrives on the same clock, once every twenty nine and a half days, roughly a fortnight after the full moon.
Why the Moon disappears
The Moon has no light of its own. It only shows us the part the Sun is lighting. At new moon the Moon sits on the same side of the sky as the Sun, so its lit face points at the Sun and its dark face points at us. It is still up there, crossing the daytime sky beside the Sun, but the side we can see is unlit. A day or two later it pulls far enough from the Sun that a thin crescent catches the light low in the evening, and the cycle begins again.
New moon and eclipses
A solar eclipse can only happen at a new moon, because that is the one time the Moon is between us and the Sun. It does not happen every month because the Moon's path is tilted a few degrees, so usually it passes a little above or below the Sun. When the alignment is exact, the new moon slides across the Sun's face and the day goes dark. The new moon is invisible every month and then, a few times a year somewhere on Earth, it becomes the most dramatic thing in the sky.
Why people track it
Farmers and gardeners have long read the new moon as the start of the cycle, the point to begin things. Fishermen watch it because new and full moons both bring the strongest tides, the spring tides, when the Sun and Moon pull in line. And anyone who wants a dark sky, to see the stars or a meteor shower or simply the depth of the night, counts the days to the new moon rather than away from it.
When the next one is
The exact date and time of the new moon move a little each month because the cycle does not fit evenly into a calendar. The live page tracks the current phase and carries the dates of both the next full moon and the next new moon, computed rather than printed, so the answer is always current.
Catch the dark sky while it lasts.
The new moon opens a short window of truly dark sky each month. Magna Earth watches that window against your coordinates and the weather and tells you the clear, moonless nights to get out under the stars, along with the meteor showers and aurora worth staying up for.
Find your dark nights — from $14/mo