Portal:Astronomy

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The Astronomy Portal

Introduction

Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry in order to explain their origin and their overall evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, meteoroids, asteroids, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole.

Astronomy is one of the oldest natural sciences. The early civilizations in recorded history made methodical observations of the night sky. These include the Egyptians, Babylonians, Greeks, Indians, Chinese, Maya, and many ancient indigenous peoples of the Americas. In the past, astronomy included disciplines as diverse as astrometry, celestial navigation, observational astronomy, and the making of calendars.

Professional astronomy is split into observational and theoretical branches. Observational astronomy is focused on acquiring data from observations of astronomical objects. This data is then analyzed using basic principles of physics. Theoretical astronomy is oriented toward the development of computer or analytical models to describe astronomical objects and phenomena. These two fields complement each other. Theoretical astronomy seeks to explain observational results and observations are used to confirm theoretical results.

Astronomy is one of the few sciences in which amateurs play an active role. This is especially true for the discovery and observation of transient events. Amateur astronomers have helped with many important discoveries, such as finding new comets. (Full article...)

General images - load new batch

The following are images from various astronomy-related articles on Wikipedia.

Image 1The Crab Nebula as seen in various wavelengths (from Observational astronomy)
Image 2"El Caracol" observatory temple at Chichen Itza, Mexico (from History of astronomy)
Image 3An image of the Cat's Paw Nebula created combining the work of professional and amateur astronomers. The image is the combination of the 2.2-metre MPG/ESO telescope of the La Silla Observatory in Chile and a 0.4-meter amateur telescope. (from Amateur astronomy)
Image 4The main platform at La Silla hosts a huge range of telescopes with which astronomers can explore the Universe. (from Observational astronomy)
Image 5Sunset at the equinox from the prehistoric site of Pizzo Vento at Fondachelli Fantina, Sicily (from History of astronomy)
Image 6A voting session is conducted in 2006 International Astronomical Union's general assembly for determining a new definition of a planet (from Astronomer)
Image 7ALMA is the world's most powerful telescope for studying the Universe at submillimeter and millimeter wavelengths. (from Observational astronomy)
Image 8The Northern Hemisphere page from Johann Bayer's 1661 edition of Uranometria - the first atlas to have star charts covering the entire celestial sphere (from History of astronomy)
Image 9Arabic astrolabe from 1079 to 1080 AD (from History of astronomy)
Image 10Historical Jantar Mantar observatory in Jaipur, India (from History of astronomy)
Image 11An amateur astrophotography setup with an automated guide system connected to a laptop (from Observational astronomy)
Image 12Southern Hemisphere (from History of astronomy)
Image 13Sir Patrick Moore was one of the world's leading popularisers of astronomy. (from Amateur astronomy)
Image 14Comparison of CMB (Cosmic microwave background) results from satellites COBE, WMAP and Planck documenting a progress in 1989–2013 (from History of astronomy)
Image 15Segment of the astronomical ceiling of Senenmut's Tomb (circa 1479–1458 BCE), depicting constellations, protective deities, and twenty-four segmented wheels for the hours of the day and the months of the year (from History of astronomy)
Image 16The Nebra sky disk, Germany, 1800 - 1600 BC (from History of astronomy)
Image 17Artist conception of the Big Bang cosmological model, the most widely accepted out of all in physical cosmology (neither time nor size to scale) (from Physical cosmology)
Image 18The Oort cloud, one of the most successful theoretical model about the Solar System (from Theoretical astronomy)
Image 19Calendrical functions of the Berlin Gold Hat c. 1000 BC (from History of astronomy)
Image 209th-century diagram of the positions of the seven planets on 18 March 816, from the Leiden Aratea (from History of astronomy)
Image 21Historical accuracy of atomic clocks from NIST. (from Theoretical astronomy)
Image 22Mayall telescope at Kitt Peak National Observatory (from Observational astronomy)
Image 23Amateur astronomy groups are often involved in outreach in order to introduce astronomy to the general public (from Amateur astronomy)
Image 24Places like Paranal Observatory offer crystal clear skies for observing astronomical objects with or without instruments. (from Amateur astronomy)
Image 25Portrait of the Flemish astronomer Ferdinand Verbiest who became Head of the Mathematical Board and Director of the Observatory of the Chinese emperor in 1669 (from Astronomer)
Image 26One of the Oldest Observatories in South America is the Quito Astronomical Observatory, founded in 1873 and located 12 minutes south of the Equator in Quito, Ecuador. The Quito Astronomical Observatory is the National Observatory of Ecuador and is located in the Historic Center of Quito and is managed by the National Polytechnic School. (from Observational astronomy)
Image 27Ultra HD photography taken at La Silla Observatory (from Observational astronomy)
Image 28An assembly in Estonia to observe meteors (from Observational astronomy)
Image 29History of the Universe – gravitational waves are hypothesized to arise from cosmic inflation, a rapidly accelerated expansion just after the Big Bang (from Physical cosmology)
$Image 3050 cm refracting telescope at Nice Observatory (from Observational astronomy)$

Image 3050 cm refracting telescope at Nice Observatory (from Observational astronomy)
Image 31Amateur astronomer recording observations of the sun. (from Amateur astronomy)
Image 32Overview of types of observational astronomy by observed wavelengths and their observability. (from Observational astronomy)
Image 33The Antikythera Mechanism was an analog computer from 150 to 100 BC designed to calculate the positions of astronomical objects. (from History of astronomy)
Image 34The Hubble Space Telescope (from History of astronomy)
Image 35Map of the Milky Way Galaxy, with the constellations that cross the galactic plane in each direction and the known prominent components annotated including main arms, spurs, bar, nucleus/bulge, notable nebulae and globular clusters (from History of astronomy)
Image 36Babylonian tablet in the British Museum recording Halley's comet in 164 BC (from History of astronomy)

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Featured article - show another

This is a Featured article, which represents some of the best content on English Wikipedia.

The Sun, captured through a clear solar filter

The Sun is the star at the center of the Solar System. It is a massive, hot ball of plasma, inflated and heated by energy produced by nuclear fusion reactions at its core. Part of this energy is emitted from its surface as visible light, ultraviolet, and infrared radiation, providing most of the energy for life on Earth. The Sun has been an object of veneration in many cultures. It has been a central subject for astronomical research since antiquity.

The Sun orbits the Galactic Center at a distance of 24,000 to 28,000 light-years. From Earth, it is on average 1 AU (1.496×10⁸ km) or about 8 light-minutes away. Its diameter is about 1,391,400 km (864,600 mi; 4.64 LS), 109 times that of Earth. Its mass is about 330,000 times that of Earth, making up about 99.86% of the total mass of the Solar System. Roughly three-quarters of the Sun's mass consists of hydrogen (~73%); the rest is mostly helium (~25%), with much smaller quantities of heavier elements, including oxygen, carbon, neon, and iron. (Full article...)

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Did you know - show different entries

... that the Lyman-alpha blob 1 is a blob of gas 300,000 light-years across located some 11.5 billion light-years from Earth?
... that 51 Ophiuchi has a disk of dust and gas that is likely a planetary system in the late stages of formation?
... that the Magellan Planet Search Program has discovered five eccentric Jupiter-mass extra-solar planets since the program started gathering data in December 2002?
... that asteroids with two moons, like 1994 CC, comprise only 1% of the near-Earth objects?
... that pictures by amateur astrophotographer Steve Mandel help to explore faint nebulae of the Milky Way?

More Did you know facts

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... that examples of artificial planets in science fiction include Riverworld, the Well World, and the Death Star?
... that Michael Collins has been called "one of the best clarinettists walking the planet" by The Times?
... that Nandivada Rathnasree, who ran Delhi's planetarium, proposed that astronomers could be taught using India's stone-built observatories?
... that in many works of fiction, the asteroid belt is the remnants of a destroyed planet?
... that in early depictions of Uranus in fiction, the planet was portrayed as solid
... that Susan Murabana created Africa's first permanent planetarium?

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WikiProjects

WikiProject Astronomy	WikiProject Solar System



WikiProject Cosmology	WikiProject Spaceflight

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Selected image - show another

Credit: NASA / ESA

The stellar nursery LH 95, in the Large Magellanic Cloud. The Initial Mass Function of LH 95 does not seem to differ from that typical for the Milky Way galaxy. Image of the Large Magellanic Cloud, a dwarf galaxy. At a distance of 163,000 light-years, it is the third closest galaxy to the Milky Way.

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Astronomy News

20 February 2024 –: Astronomers identify the most luminous object ever observed, QSO J0529-4351, a quasar that accretes around one solar mass per day. (The Guardian) (Nature.com)
24 November 2023 –: Astronomers at the Telescope Array Project in Utah, United States, observe the second largest cosmic ray ever detected, the so-called Amaterasu particle, with an energy of 244 EeV. (Cosmos Magazine)

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May anniversaries

1 May 1959 – The former Beltsville Center is renamed to Goddard Space Flight Center in honor of Dr. Robert H. Goddard, rocket pioneer who achieved first launch of a liquid-fueled rocket
4 May 1967 – Lunar Orbiter 4 is launched to perform a photographic survey of lunar surface features
7 May 1975 – Explorer 53 (SAS-C), a NASA X-ray astronomy space telescope, is launched from the San Marco Range in Kenya, Africa
7 May 1997 – English-language French science fiction action film, The Fifth Element is released showing passenger inter-constellation vehicles, spacefighter craft, and various non-human creatures
14 May 1935 – The planetarium at Griffith Observatory in Los Angeles, California opens
14 May 1973 – The first American space station, Skylab, is launched
18 May 1969 – The Apollo 10 human spaceflight is launched, testing all aspects of the lunar landing mission, except the actual lunar landing
20 May 1978 – Pioneer Venus is launched from Cape Canaveral, Florida becoming the first spacecraft placed in orbit around Venus
30 May 1971 – Mariner 9 robotic space probe is launched becoming the first spacecraft to orbit Mars