Right ascension, in astronomy, one of the coordinates in the equatorial coordinate system. The right ascension of a celestial body is the angular distance measured eastward from the vernal equ...

Ascension, name usually given to the departure of Jesus from earth as related in the Gospels according to Mark (16) and Luke (24) and in Acts 1.1–11. The annual commemoration of this is one of...

Hour circle, in astronomy, a secondary axis in the equatorial coordinate system. The hour circle of a celestial body is the great circle on the celestial sphere that passes through both the bo...

Olives, Mount of, or Olivet, ridge, E of Jerusalem, mentioned in the Old Testament as the scene of David's flight from the city, Ezekiel's theophany, and Zechariah's prophecy, and in the New T...

Rogation Days, in the calendar of the Western Church, four days traditionally set apart for solemn processions to invoke God's mercy. They are Apr. 25, the Major Rogation, coinciding with St. ...

Glasnost, Soviet cultural and social policy of the late 1980s. Following his ascension to the leadership of the USSR in 1985, Mikhail Gorbachev began to promote a policy of openness in public ...

Gay-Lussac, Joseph Louis, 1778–1850, French chemist and physicist. He was professor in Paris at the Sorbonne, at the Polytechnic School, and at the Jardin des Plantes. Gay-Lussac made two ball...

Saint Helena, island, 47 sq mi (122 sq km), in the S Atlantic Ocean, 1,200 mi (1,931 km) W of Africa. Together with the islands of Ascension and Tristan da Cunha, it comprises the British depe...

Equatorial coordinate system, the most commonly used astronomical coordinate system for indicating the positions of stars or other celestial objects on the celestial sphere. The celestial sphe...

Bethany. 1 Village, at the southeastern foot of the Mount of Olives, the modern El Aziriye, 2 mi (3.2 km) E of Jerusalem. In the Gospels, it is the home of Lazarus, Martha, and Mary. An import...