Calendar

Christmas Eve

Christmas Eve is on December 24 and marks the culmination of the Advent period before Christmas that starts on the fourth Sunday before Christmas Eve. Many churches mark the end of Advent with midnight church services. During modern times, it is popularly celebrated on the night before Christmas Day. - National Today

New Year’s Day

The year in the Roman calendar naturally starts on March 1. After all, the words September, October, November, and December literally mean Seventh Month, Eighth Month, Ninth Month, and Tenth Month, respectively. Keeping track of the passage of years was primarily the concern of those keeping historical records. Ordinary people were not particularly concerned with […]

Feast of the Epiphany

Epiphany also known as Theophany in the east, is a Christian feast day that celebrates the revelation (theophany) of God incarnate as Jesus Christ. Articles about the Feast of the Epiphany on the VO Faith and Science Archive.  

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.

Inf. Conjunction of Mercury

Mercury passes very close to the Sun in the sky as its orbit carries it between the Sun and Earth. This happens once in 116 days (the synodic cycle of the planet), and over the course of a couple weeks, Mercury will change from appearing in the evening sky to appearing in the morning sky.

Moon at Apogee

The Moon’s distance from Earth varies throughout its monthly orbit because the Moon’s orbit isn’t perfectly circular. Every month, the Moon’s eccentric orbit carries it to apogee – its most distant point from Earth – and then, some two weeks later, to perigee – the Moon’s closest point to Earth in its monthly orbit. - earthsky.org

Martin Luther King Jr. Day.

"Martin Luther King Jr. (January 15, 1929 – April 4, 1968) was an American Baptist minister and activist who became the most visible spokesperson and leader in the civil rights movement from 1955 until his assassination in 1968. Born in Atlanta, King is best known for advancing civil rights through nonviolence and civil disobedience, tactics his Christian beliefs and the nonviolent activism of Mahatma Gandhi helped inspire." - Wikipedia

New Moon

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 in shadow then. Pictured here is the traditional New Moon, the earliest visible waxing crescent, which signals the start of a new month in many […]

International Holocaust Remembrance Day

The United Nations General Assembly designated January 27—the anniversary of the liberation of Auschwitz-Birkenau—as International Holocaust Remembrance Day. On this annual day of commemoration, the UN urges every member state to honor the six million Jewish victims of the Holocaust and millions of other victims of Nazism and to develop educational programs to help prevent future genocides. […]

Official Calendar

2025 VO Calendar

Vatican Observatory 2025 astrophoto calendars now available for purchase in our e-store!