Moon

The Moon is, surprisingly, trickier to perform calculations for. While the maths is no different, the Moon is so near that even small variations in the orbital parameters or the observer’s location can cause large changes in the apparent position in the sky. Furthermore, unlike other solar system bodies, the Moon is observable for almost the entire month except for a few hours around the point of New Moon so a calculation of “observability” is pretty uninformative.

Instead here I show the rise and set times plus the RA, Dec and phase of the moon as at 00:00. The phase and position change quite quickly so you should interpolate for times later in the day. For example if the phase is 60% at midnight and 50% at midnight the next day, then around noon it will be 55%.

Note: Rise/Set is defined as when the Moon is 0.833 degrees below the horizon. This corresponds to when the upper limb is just touching the mathematical horizon, taking into account atmospheric refraction. Of course, your local horizon may be higher, or lower, than the mathematical line.

A CSV version of the data can be downloaded here