International Chernobyl Disaster Remembrance Day
An explosion at the Chernobyl Nuclear Power Plant in 1986 spread a radioactive cloud over large parts of the Soviet Union; millions of people in the three countries were exposed to the radiation.
Calendar
39 events found.
World Day for Safety and Health at Work
The World Day for Safety and Health at Work will focus on addressing the outbreak of infectious diseases at work, in particular, on the COVID-19 pandemic.
Cinco de Mayo
Mother's Day in the United States is an annual holiday celebrated on the second Sunday in May. Mother's Day recognizes mothers, motherhood and maternal bonds in general, as well as the positive contributions that they make to society. It was established by Anna Jarvis, with the first official Mother's Day celebrated through a service of worship at St. Andrew's Methodist […]
Mother’s Day (USA)
Mother's Day in the United States is an annual holiday celebrated on the second Sunday in May. Mother's Day recognizes mothers, motherhood and maternal bonds in general, as well as the positive contributions that they make to society. It was established by Anna Jarvis, with the first official Mother's Day celebrated through a service of worship at St. Andrew's Methodist […]
World Metrology Day.
World Metrology Day is an annual celebration of the signature of the Metre Convention on 20 May 1875 by representatives of seventeen nations. The Convention set the framework for global collaboration in the science of measurement and in its industrial, commercial and societal applications. The original aim of the Metre Convention - the world-wide uniformity […]
Casa Faith & Science Series at the Franciscan Renewal Center
Volunteers from the Vatican Observatory Foundation will discuss the Church’s historical views on the interaction of Faith and Science as well as theological thoughts based on the book Science and Faith by John Haught. The event will begin in the San Damiano Auditorium, and will conclude with a short walk to the back of the […]
Towel Day
Towel Day is an annual celebration on the 25th of May, as a tribute to the late author Douglas Adams (1952-2001). On that day, fans around the universe carry a towel in his honor. Towel Day 2021 marks the 43rd anniversary of the first BBC broadcast of The Hitchhiker’s Guide to the Galaxy (1978).
Memorial Day
Memorial Day is an American holiday, observed on the last Monday of May, honoring the men and women who died while serving in the U.S. military. Memorial Day 2021 will occur on Monday, May 31. Originally known as Decoration Day, it originated in the years following the Civil War and became an official federal holiday […]
Ascension
The Ascension Day of Jesus Christ always falls on a Thursday - it is the day when Christians celebrate the ascension of Jesus Christ into heaven as recorded in the Bible.
World Bicycle Day.
In April 2018, the United Nations General Assembly declared June 3 as International World Bicycle Day. The resolution for World Bicycle Day recognizes "the uniqueness, longevity and versatility of the bicycle, which has been in use for two centuries, and that it is a simple, affordable, reliable, clean and environmentally fit sustainable means of transport." Read More: https://www.un.org/en/observances/bicycle-day https://en.wikipedia.org/wiki/World_Bicycle_Day
Venus at Aphelion.
Venus's 225-day orbit around the Sun will carry it to its furthest point to the Sun – its aphelion – at a distance of 0.73 AU.
Charles Babbage’s paper on the difference engine, 1822
Charles Babbage (1791-1871), computer pioneer, designed two classes of engine, Difference Engines, and Analytical Engines. Difference engines are so called because of the mathematical principle on which they are based, namely, the method of finite differences. The beauty of the method is that it uses only arithmetical addition and removes the need for multiplication and […]
Summer Solstice
The summer solstice is the day when the Sun appears to reach its highest point in the sky during the year - it marks the start of summer in the Northern Hemisphere.
International Asteroid Day
International Asteroid Day is a United Nations-recognized day observed each year on the anniversary of the Tunguska impact event of June 30, 1908.
Canada Day.
Canada Day (French: Fête du Canada) is the national day of Canada. A federal statutory holiday, it celebrates the anniversary of July 1, 1867, the effective date of the Constitution Act, 1867 (then called the British North America Act, 1867), which united the three separate colonies of the Province of Canada, Nova Scotia, and New Brunswick into a single Dominion within the British Empire […]
Thomas Harriot, mapped the Moon with a telescope 4 months before Galileo (d. 1621)
Thomas Harriot was an English astronomer, mathematician, ethnographer and translator who made advances within the scientific field. Thomas Harriot was recognized for his contributions in astronomy, mathematics, and navigational techniques. Harriot worked closely with John White to create advanced maps for navigation. While Harriot worked extensively on numerous papers on the subjects of astronomy, mathematics and navigation, the amount of work that he actually […]
Earth at Aphelion
Earth will be at the farthest point in its orbit around the Sun on this date
Independence Day (USA)
Independence Day is a U.S. federal holiday commemorating the Declaration of Independence of the United States, on July 4, 1776.
NASA’s Pathfinder lands on Mars, 1977
Mars Pathfinder was launched December 4, 1996 and landed on Mars' Ares Vallis on July 4, 1997.
Full Moon Zoom with Sean van Staden, S.J.
Virtual Event
Join us on July 10th for our next Full Moon-th On-line Meetup! Our guest will be Sean van Staden SJ., a Jesuit scholastic about to begin his Theology studies at Hekima College in Nairobi, Kenya. He was one of the participants of the 2025 Vatican Observatory Summer School in Castel Gandolfo. Click Here to read post with more […]
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.
Thomas Kuhn born 1922
Thomas Samuel Kuhn (1922–1996) is one of the most influential philosophers of science of the twentieth century,
J. G. Mendel born 1822
Gregor Johann Mendel (1822– 1884) was a biologist, meteorologist, mathematician, Augustinian friar and abbot of St. Thomas' Abbey in Brünn (Brno), Margraviate of Moravia.
St. Ignatius Loyola, Founder of the Jesuits.
Ignatius of Loyola (Basque: Ignazio Loiolakoa; Spanish: Ignacio de Loyola; Latin: Ignatius de Loyola; c. 23 October 1491 – 31 July 1556) was a Spanish Basque Catholic priest and theologian, who co-founded the religious order called the Society of Jesus (Jesuits) and became its first Superior General at Paris in 1541. The Jesuit order served the Pope as missionaries, and they were bound by a vow of special obedience to the sovereign pontiff in […]
First Quarter Moon 2025
The Moon is at First quarter on this date -it will be visible high in the southern sky in early evening.
St Dominic, Patron of Astronomers, d. 1221
The liturgical celebration of St Dominic is on August 6 which is his deathday, in 1221 - his birthday is August 8.
Many sources state that St Dominic is the patron saint of astronomy and astronomers.
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.
VOF Moonth-ly Meetup with Saige Wilson
Join us for a Full Moon Meetup with Saige Wilson, the VOF's 2025 summer intern
Perseids Meteor Shower
The Perseids are the most popular meteor shower as they peak on warm August nights as seen from the northern hemisphere. The Perseids are active from July 17 to August 24, peaking on August 12 - 13.
Perseids Meteor Shower 2025
The Perseids are the most popular meteor shower - they peak on the evening of Aug. 12-13, 2025
Assumption of the Blessed Virgin Mary
The Assumption of the Blessed Virgin Mary is, according to the beliefs of numerous Churches, the bodily taking up of Mary, the mother of Jesus, into Heaven at the end of her earthly life. The analogous feast in the Eastern Churches is known as the Dormition of the Theotokos. In the churches that observe it, the Assumption is a major feast day, commonly celebrated on 15 […]
Last Quarter Moon 2025
The Moon is at Last Quarter (or Third Quarter) – rising around midnight, and visible to the south after sunrise.
Last Quarter Moon
The Moon is at Last Quarter (or Third Quarter) – rising around midnight, and visible to the south after sunrise.
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 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 […]