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 main platform at La Silla hosts a huge range of telescopes with which astronomers can explore the Universe. (from Observational astronomy)
$Image 250 cm refracting telescope at Nice Observatory (from Observational astronomy)$

Image 250 cm refracting telescope at Nice Observatory (from Observational astronomy)
Image 3The Oort cloud, one of the most successful theoretical model about the Solar System (from Theoretical astronomy)
Image 4Calendrical functions of the Berlin Gold Hat c. 1000 BC (from History of astronomy)
Image 5Segment 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 6The Crab Nebula as seen in various wavelengths (from Observational astronomy)
Image 7The Nebra sky disk, Germany, 1800 - 1600 BC (from History of astronomy)
Image 8Historical Jantar Mantar observatory in Jaipur, India (from History of astronomy)
Image 9Ultra HD photography taken at La Silla Observatory (from Observational astronomy)
Image 10A voting session is conducted in 2006 International Astronomical Union's general assembly for determining a new definition of a planet (from Astronomer)
Image 11History 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 12Amateur astronomy groups are often involved in outreach in order to introduce astronomy to the general public (from Amateur astronomy)
Image 13The Antikythera Mechanism was an analog computer from 150 to 100 BC designed to calculate the positions of astronomical objects. (from History of astronomy)
Image 14Southern Hemisphere (from History of astronomy)
Image 15Babylonian tablet in the British Museum recording Halley's comet in 164 BC (from History of astronomy)
Image 16An amateur astrophotography setup with an automated guide system connected to a laptop (from Observational astronomy)
Image 17Overview of types of observational astronomy by observed wavelengths and their observability. (from Observational astronomy)
Image 18An 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 19"El Caracol" observatory temple at Chichen Itza, Mexico (from History of astronomy)
Image 20Historical accuracy of atomic clocks from NIST. (from Theoretical astronomy)
Image 21Comparison of CMB (Cosmic microwave background) results from satellites COBE, WMAP and Planck documenting a progress in 1989–2013 (from History of astronomy)
Image 22Amateur astronomer recording observations of the sun. (from Amateur astronomy)
Image 23Mayall telescope at Kitt Peak National Observatory (from Observational astronomy)
Image 24Map 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 25Sunset at the equinox from the prehistoric site of Pizzo Vento at Fondachelli Fantina, Sicily (from History of astronomy)
Image 26Arabic astrolabe from 1079 to 1080 AD (from History of astronomy)
Image 27ALMA is the world's most powerful telescope for studying the Universe at submillimeter and millimeter wavelengths. (from Observational astronomy)
Image 289th-century diagram of the positions of the seven planets on 18 March 816, from the Leiden Aratea (from History of astronomy)
Image 29The 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 30Artist 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 31Places like Paranal Observatory offer crystal clear skies for observing astronomical objects with or without instruments. (from Amateur astronomy)
Image 32The Hubble Space Telescope (from History of astronomy)
Image 33One 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 34Sir Patrick Moore was one of the world's leading popularisers of astronomy. (from Amateur astronomy)
Image 35Portrait 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 36An assembly in Estonia to observe meteors (from Observational 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 Kuiper belt (/ˈkaɪpər/ KY-pər) is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune at 30 astronomical units (AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but is far larger—20 times as wide and 20–200 times as massive. Like the asteroid belt, it consists mainly of small bodies or remnants from when the Solar System formed. While many asteroids are composed primarily of rock and metal, most Kuiper belt objects are composed largely of frozen volatiles (termed "ices"), such as methane, ammonia, and water. The Kuiper belt is home to most of the objects that astronomers generally accept as dwarf planets: Orcus, Pluto, Haumea, Quaoar, and Makemake. Some of the Solar System's moons, such as Neptune's Triton and Saturn's Phoebe, may have originated in the region.

The Kuiper belt is named in honor of the Dutch astronomer Gerard Kuiper, who conjectured the existence of the belt in 1951. There were researchers before and after him who also speculated on its existence, such as Kenneth Edgeworth in the 1930s. The astronomer Julio Angel Fernandez published a paper in 1980 suggesting the existence of a comet belt beyond Neptune which could serve as a source for short-period comets. (Full article...)

List of featured articles

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Did you know - show different entries

... that the new Astronomy and Astrophysics Decadal Survey lays out a roadmap for exploring extrasolar planetary systems and investigating the nature of dark energy?
... that the constellation of Microscopium can't be seen from locations affected by light pollution?
... that the atmosphere of Triton produces a surface pressure only 1/70,000th of that on Earth?
... that in May 2008, an amateur astronomer discovered an unusual supernova-like object in the galaxy NGC 300?
... that the "Beethoven Burst" was a powerful gamma-ray burst which occurred on the birthday of Ludwig van Beethoven?

More Did you know facts

More Did you know (auto generated)

... that the Springfield Science Museum is home to the oldest operating projection planetarium in the United States?
... that the star TRAPPIST-1 has seven planets, several of which may have temperatures that would allow the existence of liquid water (artist's impression depicted)?
... that in early depictions of Uranus in fiction, the planet was portrayed as solid
... that Jessen's icosahedron has been used for both the "Skwish" children's toy and a NASA proposal for a "super ball bot" to cushion space landers on other planets?
... that the active galaxy 3C 120 was given the variable-star designation BW Tauri because of its variability in the visible spectrum?
... that fictional depictions of Jupiter have portrayed human habitation on the planet and its moons both by altering the environment to suit humans and altering humans to be suited to the environment?

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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 / Andrew Fruchter (STScI) / ERO team (STScI + ST-ECF)

The Eskimo Nebula (NGC 2392), also known as the Clown-faced Nebula, Lion Nebula or Caldwell 39, is a bipolar planetary nebula (PN) discovered by astronomer William Herschel in 1787. Image of NGC 2392, the Eskimo Nebula is by HST in 1999.

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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)

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June anniversaries

2 June 1966 – Surveyor 1 lands on the moon, first US spacecraft to do so
3 June 1966 – Gemini 9 (Gemini Titan 9A) launch from Cape Canaveral, Florida
19 June 1976 – The Viking 1 orbiter arrives in Mars orbit
24 June 2004 – First private spaceflight, SpaceShipOne piloted by Mike Melvill
27 June 1996 – Galileo probe, flyby of Ganymede (Jupiter's largest moon)
30 June 2001 – The NASA Explorer mission, MAP (Microwave Anisotropy Probe), is launched to measure the temperature of cosmic background radiation (remnant heat from the Big Bang)