Calendar

Earth at Aphelion

Earth will be at the farthest point in its orbit around the Sun on this date

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.

Mercury at Aphelion

Mercury's 88-day orbit around the Sun will carry it to its furthest point to the Sun – its aphelion – at a distance of 0.47 AU.

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.

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.

Ursids Meteor Shower

The Ursids peak just before Christmas with rates of 5-10 meteors per hour during the late morning hours.