‘Space’ Archives
Pioneer Venus
Pioneer Venus Pioneer Venus is a national aeronautics and space administration (NASA) mission to explore Venus with an orbiter and four small atmospheric probes. The PIONEER Venus 1 orbiter (also known as Pioneer 12) was launched on 1978 May 20; it entered an elliptical orbit around Venus on December 4. From this 24-hour orbit, the radar mapper [...]
Neutrino Astronomy
Neutrino Astronomy Neutrino astronomy is the study of bodies in the Universe via their emission of neutrinos. The neutrino is an electrically neutral subatomic particle whose existence was first suggested in 1930 by the Austrian physicist Wolfgang Pauli (1900–1958) in order to account for the apparent non-conservation of energy in decays. The [...]
Friedrich Wilhelm Bessel
Friedrich Wilhelm Bessel (1784–1846) Friedrich Wilhelm Bessel was a German astronomer and mathematician who was the first to measure stellar PARALLAX. In 1804, while employed as a shipping clerk, he calculated the orbit of Halley’s Comet, which impressed Wilhelm OLBERS sufficiently to recommend that he be hired as assistant to Johann [...]
Orion
Orion Generally regarded as the most splendid constellation of all, lying squarely on the celestial equator and hence equally well seen from both hemispheres. In Greek mythology, Orion was a great hunter, the son of Poseidon, but was stung to death by a scorpion, now represented by the constellation Scorpius. In the sky, Orion’s dogs follow [...]
Observatory
Observatory Observatory is any facility specifically for making celestial observations and measurements. Some structures such as Stonehenge may well have been used for observations. The observatory proper evolved from Babylonian constructions set up for astrological observation from about 750 BC, and reached a high state of scientific [...]
Black Drop
Black Drop Black Drop is the optical effect observed during the initial (ingress) and final (egress) stages of a TRANSIT of MERCURY or VENUS. Once the planet is fully projected on the Sun at ingress, but before its trailing edge breaks apparent contact with the solar limb, the expectation is of instantaneous separation. Instead, the planet [...]
Nuclear Reactions
Nuclear Reactions Nuclear Reactions are Interactions between atomic nuclei or between atomic nuclei and subatomic particles or gamma rays. Nuclear reactions produce transformations from one element or isotope to another. There are two basic types of reaction, fusion and fission. The main astronomical occurrences of fusion are within stellar [...]
Paris Observatory
Paris Observatory Paris Observatory is the second-oldest observatory in the world, after copenhagen observatory. The ‘Observatoire de Paris’ was commissioned by King Louis XIV principally for geodesy, and built in 1667. Many famous 17th-century astronomers worked there, including Jean Picard, Ole RÖMER, Christiaan HUYGENS, Nicolas-Louis de [...]
First Point of Aries
First Point of Aries First Point of Aries Position on the CELESTIAL SPHERE where the Sun’s centre crosses the celestial equator from south to north at the time of the VERNAL EQUINOX, on or around March 21 each year. This marks the intersection of the ECLIPTIC with the CELESTIAL EQUATOR at the Sun’s ASCENDING NODE; it is used as the zero [...]
Indian Astronomy
Indian Astronomy Indian astronomy is astronomy as practised in India from ancient times until the 18th century, when Western European astronomy became prevalent. The precise origins of Indian astronomy are unknown, but probably date from the Indus Valley civilization (c.2000 BC). Some practical astronomy existed during the Vedic period, which [...]
