Calendar

Full Moon

The Full Moon rises at sunset, and is visible all night. The Vatican Observatory's monthly Full Moon Meetup for Sacred Space Astronomy subscribers is held at 10:00 AM Tucson time.

New Moon 2025

New Moon. By the modern definition, New Moon occurs when the Moon and Sun are at the same geocentric ecliptic longitude. The part of the Moon facing us is completely […]

Autumnal Equinox

Fall begins with the autumnal equinox - in the Northern Hemisphere, it's the September equinox; in the Southern Hemisphere, it is the equinox in March.

Venus at Perihelion

The planet Venus is a Perihelion (its closest approach to the Sun) on this date.

Uranus at Opposition

Uranus will be in opposition to the Sun on this date; this is when the Earth is positioned between the Sun and Uranus. 

Winter Solstice

The winter solstice, also called the hibernal solstice, occurs when either of Earth's poles reaches its maximum tilt away from the Sun.