Phases glossary
What is a new Moon?
New Moon is the phase when the Moon is near the Sun in Earth's sky and its illuminated hemisphere faces mostly away from Earth.
What it means
New Moon belongs to the Moon's repeating cycle of illumination. Lunar phases are produced by the changing Sun-Earth-Moon geometry, not by Earth's shadow; Earth's shadow is involved only during a lunar eclipse. The same phase is visible worldwide at a given moment, although its orientation can look different by latitude and hemisphere.
For a deeper look with practical observing advice, read the Moonrise Moment guide to new moon.
Sources and further reading
This definition was written in plain language and checked against these science references.