Moon

Explore Moon position, phases, astronomical new moon and traditional molad comparisons, with rise/transit/set, observer views and lunar geometry.

Explore lunar phases, illumination, altitude, direction, rise and set events at a chosen time and location. The observation viewer includes a horizon, altitude guides, building-height comparisons and time jumps. Lunar views use the standard Hebrew calendar.

A traditional mean molad, a calculated true conjunction and the first visible crescent are different events. Compare the Moon with the Sun and observer horizon; illumination alone does not establish visibility. Calendar changes based on sightings belong to the separate experimental-year and sighting-calendar tools.

Jewish Cosmology is an interactive research and educational web application connecting Hebrew dates, traditional Jewish calendar calculations and halachic concepts of time with the observable motions of the Sun, Moon and planets, astronomical seasons and eclipses.

JavaScript is required for the interactive explorers and calculations. The descriptions and navigation remain available without JavaScript.