Using the Moon Phase Tool
These guides on using the Moon Phase tool cover reading tonight's phase, finding the next full or new moon, and timing a night under a dark sky — practical, no-jargon advice.
How to Use the Moon Phase Tool
Read tonight's phase and illumination, find the next full and new moon, add moonrise/moonset, and scan the 30-day calendar.
Read TipsThe Best Moon Phase for Stargazing
Why a bright moon washes out faint stars, which phases give the darkest skies, and how to time a session.
ReadThe Moon Phase tool calculates tonight's phase, illumination percentage, moonrise and moonset for any location entirely in your browser, using well-known orbital maths rather than a lookup API, plus a 30-day calendar so you can see the next full and new moon at a glance. These guides go beyond the interface itself: they cover how to read the illumination percentage alongside the phase name, why the exact moment of "full" is a single instant even though the moon looks full for a couple of nights either side, and how moonrise time shifts by roughly fifty minutes a day as the month goes on.
If you're planning a night of stargazing or astrophotography, the moon is usually the biggest variable: a bright gibbous or full moon washes out faint stars and the Milky Way, while a new moon or thin crescent gives the darkest possible sky. The stargazing guide covers which phases to target, how many nights either side of new moon still count as "dark enough," and how to combine the moon calendar here with the weather forecast to check cloud cover before you head out.