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.

$Image 150 cm refracting telescope at Nice Observatory (from Observational astronomy)$

Image 150 cm refracting telescope at Nice Observatory (from Observational astronomy)
Image 2Historical accuracy of atomic clocks from NIST. (from Theoretical astronomy)
Image 3Comparison of CMB (Cosmic microwave background) results from satellites COBE, WMAP and Planck documenting a progress in 1989–2013 (from History of astronomy)
Image 4Babylonian tablet in the British Museum recording Halley's comet in 164 BC (from History of astronomy)
Image 5The Nebra sky disk, Germany, 1800 - 1600 BC (from History of astronomy)
Image 6Mayall telescope at Kitt Peak National Observatory (from Observational astronomy)
Image 7History 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 8The main platform at La Silla hosts a huge range of telescopes with which astronomers can explore the Universe. (from Observational astronomy)
Image 9Overview of types of observational astronomy by observed wavelengths and their observability. (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 11Historical Jantar Mantar observatory in Jaipur, India (from History of astronomy)
Image 12Map 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 13Arabic astrolabe from 1079 to 1080 AD (from History of astronomy)
Image 14The Crab Nebula as seen in various wavelengths (from Observational astronomy)
Image 15An assembly in Estonia to observe meteors (from Observational astronomy)
Image 16The Oort cloud, one of the most successful theoretical model about the Solar System (from Theoretical astronomy)
Image 17An 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 18The 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 19Sir Patrick Moore was one of the world's leading popularisers of astronomy. (from Amateur astronomy)
Image 20The Hubble Space Telescope (from History of astronomy)
Image 21Calendrical functions of the Berlin Gold Hat c. 1000 BC (from History of astronomy)
Image 22Amateur astronomer recording observations of the sun. (from Amateur astronomy)
Image 239th-century diagram of the positions of the seven planets on 18 March 816, from the Leiden Aratea (from History of astronomy)
Image 24"El Caracol" observatory temple at Chichen Itza, Mexico (from History of astronomy)
Image 25Artist 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 26The Antikythera Mechanism was an analog computer from 150 to 100 BC designed to calculate the positions of astronomical objects. (from History of astronomy)
Image 27Portrait 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 28Ultra HD photography taken at La Silla Observatory (from Observational astronomy)
Image 29An amateur astrophotography setup with an automated guide system connected to a laptop (from Observational astronomy)
Image 30Amateur astronomy groups are often involved in outreach in order to introduce astronomy to the general public (from Amateur astronomy)
Image 31One 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 32ALMA is the world's most powerful telescope for studying the Universe at submillimeter and millimeter wavelengths. (from Observational astronomy)
Image 33Places like Paranal Observatory offer crystal clear skies for observing astronomical objects with or without instruments. (from Amateur astronomy)
Image 34Sunset at the equinox from the prehistoric site of Pizzo Vento at Fondachelli Fantina, Sicily (from History of astronomy)
Image 35Southern Hemisphere (from History of astronomy)
Image 36Segment 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)

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Featured article - show another

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

Earthrise
Taken from Apollo 8 by William Anders

Apollo 8 (December 21–27, 1968) was the first crewed spacecraft to leave Earth's gravitational sphere of influence, and the first human spaceflight to reach the Moon. The crew orbited the Moon ten times without landing, and then departed safely back to Earth. These three astronauts—Frank Borman, James Lovell, and William Anders—were the first humans to witness and photograph the far side of the Moon and an Earthrise.

Apollo 8 launched on December 21, 1968, and was the second crewed spaceflight mission flown in the United States Apollo space program after Apollo 7, which stayed in Earth orbit. Apollo 8 was the third flight and the first crewed launch of the Saturn V rocket, and was the first human spaceflight from the Kennedy Space Center, located adjacent to Cape Kennedy Air Force Station in Florida. (Full article...)

List of featured articles

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Did you know - show different entries

... that Oscar Monnig donated one of the largest private collections of meteorites to Texas Christian University?
... that at first light in 1987, the William Herschel Telescope was the third largest single optical telescope in the world, and is still the second largest in Europe?
... that a Bok globule is a dark cloud of dense dust and gas, first observed by astronomer Bart Bok in the 1940s, in which star formation is taking place within the H II region?
... that the aerial telescope is a type of very long focal length refracting telescope built in the second half of the 17th century that did not use a tube?
... that the galaxy pair Arp 147 contains a ring of nine black holes?

More Did you know facts

More Did you know (auto generated)

... that King Gizzard & the Lizard Wizard's "cli-fi" thrash metal album addresses a mix of current ecological threats and attempts to find another planet to live on?
... 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?
... that in early depictions of Uranus in fiction, the planet was portrayed as solid
... 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 the active galaxy 3C 120 was given the variable-star designation BW Tauri because of its variability in the visible spectrum?
... that the Springfield Science Museum is home to the oldest operating projection planetarium in the United States?

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WikiProjects

WikiProject Astronomy	WikiProject Solar System



WikiProject Cosmology	WikiProject Spaceflight

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Selected image - show another

Credit: NASA

Sunspots are temporary phenomena on the surface of the Sun (the photosphere) that appear visibly as dark spots compared to surrounding regions. They are caused by intense magnetic activity, which inhibits convection, forming areas of reduced surface temperature. Although they are at temperatures of roughly 3,000–4,500 K (4,940–7,640 °F), the contrast with the surrounding material at about 5,780 K leaves them clearly visible as dark spots, as the intensity of a heated black body (closely approximated by the photosphere) is a function of T (temperature) to the fourth power.

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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)