Calendar

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 […]

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

Eid al-Fitr begins at sundown (Muslim)

Eid al-Fitr (/iːd əl ˈfɪtər/ eed əl FIT-ər; Arabic: عيد الفطر‎ ʻĪd al-Fiṭr, IPA: ), also called the "Festival of Breaking the Fast" or Lesser Eid, is a religious holiday celebrated by Muslims worldwide that marks the end of the month-long dawn-to-sunset fasting of Ramadan. This religious Eid is the only day in the month of Shawwal during which Muslims are not permitted to fast. The date for the start of any lunar Hijri month varies based […]

Astronomy Day

Astronomy Day is an international event observed each fall and spring near the first quarter Moon. Local astronomical societies, planetariums, museums, and observatories sponsor public viewing sessions, presentations, workshops, and other activities to increase public awareness about astronomy and our wonderful universe.

Astronomy Day

Astronomy Day is an international event observed each fall and spring near the first quarter Moon. Local astronomical societies, planetariums, museums, and observatories sponsor public viewing sessions, presentations, workshops, and other activities to increase public awareness about astronomy and our wonderful universe.

This fall, Astronomy Day will be held on October 12, 2021.

Conjunction of Mars & Moon

The planet Mars will appear in conjunction with the Moon in the western sky after sunset on this May 15, 2021.

International Day of Light

The International Day of Light is a global initiative that provides an annual focal point for the continued appreciation of light and the role it plays in science, culture and art, education, and sustainable development, and in fields as diverse as medicine, communications, and energy. The broad theme of light will allow many different sectors […]

St. Brendan, patron of navigators who steer by celestial bodies

Brendan of Clonfert (c. AD 484 – c. 577) Brénainn moccu Alti or Brénainn maccu Alti (Irish: Naomh Bréanainn or Naomh Breandán; Latin: Brendanus; Icelandic: (heilagur) Brandanus), also referred to as "Brendán moccu Altae" (Brendan of the Fosterling Folk), called "the Navigator", "the Voyager", "the Anchorite", and "the Bold", is one of the early Irish monastic saints and one of the Twelve Apostles of Ireland. He is primarily renowned for his legendary […]

World Telecommunication and Information Society Day

Theme: "Accelerating Digital Transformation in challenging times​"​. ​​ World Telecommunication and Information Society Day ​(WTISD) has been celebrated annually every 17 May since 1969 to mark the founding of ITU and the signing of the first International Telegraph Convention in 1865. The COVID-19 crisis has not only highlighted the critical role of information and communication […]

First Quarter Moon

The Moon is at First Quarter on May 19th - it is visible high in the southern sky in early evening.

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 […]

Andrei Sakharov, Nobel Laureate (b. 1921)

Andrei Dmitrievich Sakharov (21 May 1921 – 14 December 1989) was a Soviet and Russian nuclear physicist, dissident, Nobel laureate, and activist for disarmament, peace and human rights. He became renowned as the designer of the Soviet Union's RDS-37, a codename for Soviet development of thermonuclear weapons. Sakharov later became an advocate of civil liberties and civil reforms in the Soviet Union, for which […]