The Moon does not make its own light
Moonlight is sunlight reflected from the Moon's surface.
Astronomy Learning Tool
Moon Phases Learning Tool
Drag the Moon around Earth and watch the visible phase change from New Moon to Full Moon and back again through a lunar month.
Big idea: The Moon is always half lit by the Sun, but from Earth we see different amounts of that sunlit half as the Moon orbits Earth. Because the Moon is tidally locked, observers see nearly the same side of the Moon throughout the month.
New Moon
NewFirst Q.FullLast Q.New
Drag the Moon in the diagram or use this slider.
Jump to a phase
Show or hide layers
Moon phase tonight
Use the estimate for a quick phase check, or open Timeanddate for exact local moonrise and phase details.
Phase sequence
Waxing means the lit part grows. Waning means the lit part shrinks.
View from Earth
This separate view shows the phase you would see in the sky, without covering the orbit diagram.
PhaseNew Moon
Moon age0.0 days
Illuminated0%
Trendstarting
New MoonThe Moon is between Earth and the Sun. The side facing Earth is mostly dark, so the Moon is hard to see.
Illuminated fraction = (1 - cos phase angle) / 2Phase angle is measured from New Moon: 0 deg new, 90 deg first quarter, 180 deg full, 270 deg last quarter.
Eight Main Moon Phases
The duplicated Waning Gibbous label is shown once here; New Moon is included because it starts each lunar month.
What Learners Should Notice
Same side faces Earth
The Moon rotates once each orbit, so we keep seeing nearly the same lunar face from Earth.
Counter clockwise orbit
In this top-down north-pole view, the Moon moves counter clockwise around Earth.
Practice Keywords
Use this tool to explore moon phases, lunar month, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter, and waning crescent.
moon phaseslunar monthwaxing moonwaning moonilluminated fraction
References
These references support the phase sequence, illumination model, and Moon facts used in the tool.