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 1Overview of types of observational astronomy by observed wavelengths and their observability. (from Observational astronomy)
Image 2Calendrical functions of the Berlin Gold Hat c. 1000 BC (from History of astronomy)
Image 3An 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 4Map 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 5The Oort cloud, one of the most successful theoretical models about the Solar System (from Theoretical astronomy)
Image 6An 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 7The Hubble Space Telescope (from History of astronomy)
Image 8The main platform at La Silla hosts a huge range of telescopes with which astronomers can explore the Universe. (from Observational astronomy)
Image 9Segment 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 10Babylonian tablet in the British Museum recording Halley's Comet in 164 BC (from History of astronomy)
Image 11Sir Patrick Moore was one of the world's leading popularisers of astronomy. (from Amateur astronomy)
Image 12Amateur astronomy groups are often involved in outreach to introduce astronomy to the general public (from Amateur astronomy)
Image 13The 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 14Sunset at the equinox from the prehistoric site of Pizzo Vento at Fondachelli Fantina, Sicily (from History of astronomy)
Image 15A voting session is conducted in 2006 International Astronomical Union's general assembly for determining a new definition of a planet (from Astronomer)
Image 16Ultra HD photography taken at La Silla Observatory (from Observational astronomy)
Image 17"El Caracol" observatory temple at Chichen Itza, Mexico (from History of astronomy)
$Image 1850 cm refracting telescope at Nice Observatory (from Observational astronomy)$

Image 1850 cm refracting telescope at Nice Observatory (from Observational astronomy)
Image 19One 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 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 21History 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 22Amateur astronomer recording observations of the sun. (from Amateur astronomy)
Image 23Places like Paranal Observatory offer crystal clear skies for observing astronomical objects with or without instruments. (from Amateur astronomy)
Image 24The Crab Nebula as seen in various wavelengths (from Observational astronomy)
Image 25The 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 26An amateur astrophotography setup with an automated guide system connected to a laptop (from Observational astronomy)
Image 27Historical accuracy of atomic clocks from NIST. (from Theoretical astronomy)
Image 28Arabic astrolabe from 1079 to 1080 AD (from History of astronomy)
Image 299th-century diagram of the positions of the seven planets on 18 March 816, from the Leiden Aratea (from History of astronomy)
Image 30Portrait 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 31Historical Jantar Mantar observatory in Jaipur, India (from History of astronomy)
Image 32Comparison of CMB (Cosmic microwave background) results from satellites COBE, WMAP and Planck documenting a progress in 1989–2013 (from History of astronomy)
Image 33Southern Hemisphere (from History of astronomy)
Image 34An assembly in Estonia to observe meteors (from Observational astronomy)
Image 35The Nebra sky disk, Germany, 1800–1600 BC (from History of astronomy)
Image 36Mayall telescope at Kitt Peak National Observatory (from Observational astronomy)
Image 37ALMA is the world's most powerful telescope for studying the Universe at submillimeter and millimeter wavelengths. (from Observational astronomy)

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

The scattered disc (or scattered disk) is a distant circumstellar disc in the Solar System that is sparsely populated by icy small Solar System bodies, which are a subset of the broader family of trans-Neptunian objects. The scattered-disc objects (SDOs) have orbital eccentricities ranging as high as 0.8, inclinations as high as 40°, and perihelia greater than 30 astronomical units (4.5×10⁹ km; 2.8×10⁹ mi). These extreme orbits are thought to be the result of gravitational "scattering" by the gas giants, and the objects continue to be subject to perturbation by the planet Neptune.

Although the closest scattered-disc objects approach the Sun at about 30–35 AU, their orbits can extend well beyond 100 AU. This makes scattered disc objects among the coldest and most distant objects in the Solar System. The innermost portion of the scattered disc overlaps with a torus-shaped region of orbiting objects traditionally called the Kuiper belt, but its outer limits reach much farther away from the Sun and farther above and below the ecliptic than the Kuiper belt proper. (Full article...)

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Did you know - show different entries

... that 12th-century Muslim scientist Al-Khazini, who proposed a theory of gravitation long before Isaac Newton, was, in his early life, a slave of the Seljuq Turks?
... that Kepler-47c is a circumbinary planet orbiting in the habitable zone of Kepler-47, a binary star system?
... that two high school students used the automated telescope at Leuschner Observatory to record the earliest images of supernova SN 1994I?
... that the Kuiper crater in the Kuiper quadrangle, named after Dutch American astronomer Gerard Kuiper, has the highest albedo recorded on Mercury?
...that Mt. Olympus Mons on Mars is the highest peak in the solar system?

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... that Na drugą planetę, published in 1895 as one of the earliest Polish science-fiction novels, was later criticized by communist-era censors for its perceived "adoration for America"?
... that Michael Collins has been called "one of the best clarinettists walking the planet" by The Times?
... that examples of artificial planets in science fiction include Riverworld, the Well World, and the Death Star?
... that a profile of artist Mark Hearld said his "wrens and squirrels, field mice and owls" help a child care about the planet better than telling them it is burning?
... 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 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?

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WikiProjects

WikiProject Astronomy	WikiProject Solar System



WikiProject Cosmology	WikiProject Spaceflight

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Credit: NASA/ESA/AURA/Caltech

In astronomy, the Pleiades, or Seven Sisters (Messier object 45), is an open star cluster containing middle-aged hot B-type stars located in the constellation of Taurus. It is among the nearest star clusters to Earth and is the cluster most obvious to the naked eye in the night sky.

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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