New Moon – the Invisible Phase
In modern astronomy, the New Moon is when the Sun and Moon are aligned, with the Sun and Earth on opposite sides of the Moon.
There are several reasons why it is impossible for us to see the New Moon in the sky.
The alignment of the Sun, the Moon, and Earth, leaves the side of the Moon that faces Earth in complete darkness. Technically, this is called a conjunction or Syzygy in the Sun-Earth-Moon system (see illustration).
In addition, the New Moon rises and sets around the same time as the Sun, bringing it too close to the Sun’s glare to be seen with the naked eye.
New Moon in Different Cultures
About a day after the New Moon conjunction, the Moon becomes visible again as a Waxing Crescent Moon.
The initial period, as only the thinnest sliver of a Crescent Moon becomes visible and the Da Vinci glow or earthshine envelops the dark portion of the Moon, used to be called New Moon while the darkest phase was called Dark Moon.
This traditional definition of New Moon is still in use in some cultures, defining the beginning of the months in the Islamic calendar.
Higher Tides at New Moon
The greatest difference between high and low tide is around New Moon and Full Moon. During these Moon phases, the gravitational forces of the Moon and the Sun combine to push the ocean’s water in the same direction. These tides are known as spring tides or king tides.
Sun Lights Up the Moon
The Moon does not radiate its own light, but the Moon's surface reflects the Sun’s rays. Half of the Moon’s surface is always lit up by sunlight, except during lunar eclipses when Earth casts its shadow on the Moon. Just how much of that light we can see from our point of view on Earth varies every day, and this is what we call a Moon phase.
Primary Moon Phase
In Western Culture, we divide the lunar month into four primary and four intermediate Moon phases.
New Moon Symbol in Calendars
The symbol for New Moon in modern calendars is a completely black circle.
The other primary Moon phase symbols in calendars:
= First Quarter, = Full Moon, = Third Quarter
Causes Solar Eclipses
Even though the New Moon cannot normally be seen from Earth, there is an exception: 2 to 3 times a year the New Moon phase coincides with the Moon reaching the lunar nodes of its orbit. The lunar nodes are the points where the Moon's orbit crosses the ecliptic, which is the path of the Sun, seen from Earth.
At these points, the dark New Moon positions itself between Earth and the Sun and blocks some of the Sun's rays from reaching some areas on Earth, causing a solar eclipse. The New Moon, or at least a part of it, is then visible as a silhouette in front of the Sun. Solar eclipses can only happen in the hours around New Moon. Lunar eclipses, on the other hand, only happen at Full Moon.
A Black Moon Is a New Moon
Most years have 12 New Moons, 1 each month. But our calendar is not perfectly synchronized with astronomical events. Therefore, every now and then, a year has 13 Full Moons. When this happens, at least 1 of those New Moons is a Black Moon.
Super and Micro New Moon
The Moon orbits Earth counterclockwise on an elliptical path, and the same side of the Moon always faces Earth. However, the Moon rocks slightly from north to south and wobbles a little from east to west. This motion, known as lunar libration, makes it possible, over time, to see up to 58% of the Moon’s surface from Earth, but only 50% at a time.
A Micro New Moon, on the other hand, is when it is farthest from Earth, at apogee. It's also known as a Minimoon or a Mini New Moon.
No Permanently Dark Side
The notion that there is a permanently dark side of the Moon, a side which never sees sunlight, is wrong. When the side of the Moon we can see from Earth is dark, the opposite side is lit up, and vice versa.