Portal:Astronomy

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 1ALMA is the world's most powerful telescope for studying the Universe at submillimeter and millimeter wavelengths. (from Observational astronomy)
Image 2The Hubble Space Telescope (from History of astronomy)
Image 3The Crab Nebula as seen in various wavelengths (from Observational astronomy)
Image 4An 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 5Places like Paranal Observatory offer crystal clear skies for observing astronomical objects with or without instruments. (from Amateur astronomy)
Image 6The main platform at La Silla hosts a huge range of telescopes with which astronomers can explore the Universe. (from Observational astronomy)
Image 7Overview of types of observational astronomy by observed wavelengths and their observability. (from Observational astronomy)
Image 8Historical Jantar Mantar observatory in Jaipur, India (from History of astronomy)
Image 9The Oort cloud, one of the most successful theoretical models about the Solar System (from Theoretical astronomy)
Image 10Mayall telescope at Kitt Peak National Observatory (from Observational astronomy)
Image 11The Nebra sky disk, Germany, 1800–1600 BC (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 13Amateur astronomer recording observations of the sun. (from Amateur astronomy)
Image 14An amateur astrophotography setup with an automated guide system connected to a laptop (from Observational astronomy)
Image 15One 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 16Portrait 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 17Southern Hemisphere (from History of astronomy)
Image 18Babylonian tablet in the British Museum recording Halley's Comet in 164 BC (from History of astronomy)
Image 19Sunset at the equinox from the prehistoric site of Pizzo Vento at Fondachelli Fantina, Sicily (from History of astronomy)
Image 20Artist 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 21"El Caracol" observatory temple at Chichen Itza, Mexico (from History of astronomy)
Image 22Calendrical functions of the Berlin Gold Hat c. 1000 BC (from History of astronomy)
Image 23Comparison of CMB (Cosmic microwave background) results from satellites COBE, WMAP and Planck documenting a progress in 1989–2013 (from History of astronomy)
Image 24The 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 25Amateur astronomy groups are often involved in outreach to introduce astronomy to the general public (from Amateur astronomy)
Image 26The inflationary theory as an augmentation to the Big Bang theory was first proposed by Alan Guth of MIT. Inflation solves the 'horizon problem' by making the early universe much more compact than was assumed in the standard model. Given such smaller size, causal contact (i.e., thermal communication) would have been possible among all regions of the early universe. The image was an adaptation from various generic charts depicting the growth of the size of the observable universe, for both the standard model and inflationary model respectively, of the Big Bang theory. (from Physical cosmology)
Image 27An example of a gravitational lens found in the DESI Legacy Surveys data. There are four sets of lensed images in DESI-090.9854-35.9683, corresponding to four distinct background galaxies—from the outermost giant red arc to the innermost bright blue arc, arranged in four concentric circles. All of them are gravitationally warped—or lensed—by the orange galaxy at the very center. Dark matter is expected to produce gravitational lensing also. (from Physical cosmology)
Image 28Segment of the astronomical ceiling of Senenmut's Tomb (circa 1479–1458 BC), 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 29Historical accuracy of atomic clocks from NIST. (from Theoretical astronomy)
Image 30Sir Patrick Moore was one of the world's leading popularisers of astronomy. (from Amateur astronomy)
Image 31History 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 32An assembly in Estonia to observe meteors (from Observational astronomy)
Image 33Arabic astrolabe from 1079 to 1080 AD (from History of astronomy)
Image 34A voting session is conducted in 2006 International Astronomical Union's general assembly for determining a new definition of a planet (from Astronomer)
$Image 3550 cm refracting telescope at Nice Observatory (from Observational astronomy)$

Image 3550 cm refracting telescope at Nice Observatory (from Observational astronomy)
Image 369th-century diagram of the positions of the seven planets on 18 March 816, from the Leiden Aratea (from History of astronomy)
Image 37Ultra HD photography taken at La Silla Observatory (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.

Composite image using optical images from the HST and X-ray data from the Chandra X-ray Observatory.

The Cat's Eye Nebula (also known as NGC 6543 and Caldwell 6) is a planetary nebula in the northern constellation of Draco, discovered by William Herschel on February 15, 1786. It was the first planetary nebula whose spectrum was investigated by the English amateur astronomer William Huggins, demonstrating that planetary nebulae were gaseous and not stellar in nature. Structurally, the object has had high-resolution images by the Hubble Space Telescope revealing knots, jets, bubbles and complex arcs, being illuminated by the central hot planetary nebula nucleus (PNN). It is a well-studied object that has been observed from radio to X-ray wavelengths. At the centre of the Cat's Eye Nebula is a dying Wolf–Rayet star, the sort of which can be seen in the Webb Telescope's image of WR 124. The Cat's Eye Nebula's central star shines at magnitude +11.4. Hubble Space Telescope images show a sort of dart board pattern of concentric rings emanating outwards from the centre. (Full article...)

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Did you know - show different entries

... that Abell 2142, a galaxy cluster, is one of the most massive objects in the universe?
... that a jet from one of the component stars of Z Canis Majoris is over 11 light-years long?
... that Messier 58 is one of the brightest galaxies in the Virgo Cluster and is 1 of 4 barred spiral galaxies included in Charles Messier's catalog?
... that the asteroid 2014 AA entered Earth's atmosphere on the early morning of January 2, 2014, less than a day after it was discovered?
... that ATIC, a balloon-borne detector flying over Antarctica, recently found excess cosmic ray electrons that might provide evidence for dark matter consisting of Kaluza-Klein particles?
.... that the Sun fuses about 620 million metric tons of hydrogen per seconds due to Gravity?

More Did you know facts

More Did you know (auto generated)

... that one night on the planet Venus lasts just over 58 full days on Earth?
... that Susan Murabana created Africa's first permanent planetarium?
... that the majority of extrasolar planets in fiction are inhabited by native species?
... 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

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WikiProjects

WikiProject Astronomy	WikiProject Solar System



WikiProject Cosmology	WikiProject Spaceflight

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Credit: NASA

The International Space Station is photographed by an STS-134 crew member on the space shuttle Endeavour after the station and shuttle began their post-undocking relative separation. Undocking of the two spacecraft occurred on May 29, 2011.

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Astronomy News

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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)

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Space-related Portals

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Astronomical events

All times UT unless otherwise specified.

1 June, 01:59	Venus at greatest western elongation
7 June, 10:42	Moon at apogee
11 June, 07:44	Full moon
21 June, 02:42	Earth northern solstice
23 June, 04:43	Moon at perigee
24 June, 15:06	Jupiter at conjunction; occultation
25 June, 10:31	New moon
30 June, 01:05	Moon occults Mars