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 1Segment 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 2An amateur astrophotography setup with an automated guide system connected to a laptop (from Observational astronomy)
Image 39th-century diagram of the positions of the seven planets on 18 March 816, from the Leiden Aratea (from History of astronomy)
Image 4An 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 5Historical Jantar Mantar observatory in Jaipur, India (from History of astronomy)
Image 6Places like Paranal Observatory offer crystal clear skies for observing astronomical objects with or without instruments. (from Amateur astronomy)
Image 7Southern Hemisphere (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 9Comparison of CMB (Cosmic microwave background) results from satellites COBE, WMAP and Planck documenting a progress in 1989–2013 (from History of astronomy)
Image 10Map 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 11Sir Patrick Moore was one of the world's leading popularisers of astronomy. (from Amateur astronomy)
$Image 1250 cm refracting telescope at Nice Observatory (from Observational astronomy)$

Image 1250 cm refracting telescope at Nice Observatory (from Observational astronomy)
Image 13A voting session is conducted in 2006 International Astronomical Union's general assembly for determining a new definition of a planet (from Astronomer)
Image 14Mayall telescope at Kitt Peak National Observatory (from Observational astronomy)
Image 15Ultra HD photography taken at La Silla Observatory (from Observational astronomy)
Image 16An assembly in Estonia to observe meteors (from Observational astronomy)
Image 17Amateur astronomy groups are often involved in outreach to introduce astronomy to the general public (from Amateur astronomy)
Image 18Calendrical functions of the Berlin Gold Hat c. 1000 BC (from History of astronomy)
Image 19The Antikythera Mechanism was an analog computer from 150 to 100 BC designed to calculate the positions of astronomical objects. (from History of astronomy)
Image 20"El Caracol" observatory temple at Chichen Itza, Mexico (from History of astronomy)
Image 21Overview of types of observational astronomy by observed wavelengths and their observability. (from Observational astronomy)
Image 22ALMA is the world's most powerful telescope for studying the Universe at submillimeter and millimeter wavelengths. (from Observational astronomy)
Image 23Arabic astrolabe from 1079 to 1080 AD (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 25History 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 26An 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 27The Hubble Space Telescope (from History of astronomy)
Image 28The Nebra sky disk, Germany, 1800–1600 BC (from History of astronomy)
Image 29One 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 30The Crab Nebula as seen in various wavelengths (from Observational astronomy)
Image 31Babylonian tablet in the British Museum recording Halley's Comet in 164 BC (from History of astronomy)
Image 32Amateur astronomer recording observations of the sun. (from Amateur astronomy)
Image 33Sunset at the equinox from the prehistoric site of Pizzo Vento at Fondachelli Fantina, Sicily (from History of astronomy)
Image 34Historical accuracy of atomic clocks from NIST. (from Theoretical astronomy)
Image 35Artist 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 36The 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 37Portrait 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 38The Oort cloud, one of the most successful theoretical models about the Solar System (from Theoretical astronomy)

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

Seen in orbit from the departing Space Shuttle Atlantis in 2009, flying Servicing Mission 4 (STS-125), the fifth and final Hubble mission.

The Hubble Space Telescope (HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versatile, renowned as a vital research tool and as a public relations boon for astronomy. The Hubble telescope is named after astronomer Edwin Hubble and is one of NASA's Great Observatories. The Space Telescope Science Institute (STScI) selects Hubble's targets and processes the resulting data, while the Goddard Space Flight Center (GSFC) controls the spacecraft.

Hubble features a 2.4 m (7 ft 10 in) mirror, and its five main instruments observe in the ultraviolet, visible, and near-infrared regions of the electromagnetic spectrum. Hubble's orbit outside the distortion of Earth's atmosphere allows it to capture extremely high-resolution images with substantially lower background light than ground-based telescopes. It has recorded some of the most detailed visible light images, allowing a deep view into space. Many Hubble observations have led to breakthroughs in astrophysics, such as determining the rate of expansion of the universe. (Full article...)

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Did you know - show different entries

... that Caroline Moore was 14 years old when she discovered supernova 2008ha?
... that although Charles Messier discovered the galaxy M91 in 1781, it was added to his catalogue only two centuries later?
... that the fall of the Neuschwanstein meteorite in 2002 was observed by the European Fireball Network and outdoor witnesses through most of Central Europe?
... that AG Pegasi has been described as the slowest nova ever recorded?

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... 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 Michael Collins has been called "one of the best clarinettists walking the planet" by The Times?
... that in many works of fiction, the asteroid belt is the remnants of a destroyed planet?
... that the active galaxy 3C 120 was given the variable-star designation BW Tauri because of its variability in the visible spectrum?
... that 1ES 1927+654, a galaxy in Draco, exhibited such extreme nuclear activity that it challenged conventional models of black-hole environments?
... that novelist Hal Clement created the planet Mesklin in 1953 based on the real-world suspected detection of an extrasolar planet?

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WikiProjects

WikiProject Astronomy	WikiProject Solar System



WikiProject Cosmology	WikiProject Spaceflight

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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

21 November 2024 –: The European Southern Observatory announces that its astronomers in Chile capture the first close-up image of a star outside the Milky Way. (The New York Times)
20 November 2024 – Discoveries of exoplanets: In a study published by the Nature journal, astronomers announce the discovery of IRAS 04125+2902 b, a newborn exoplanet. The discovery was made by Madyson Barber, a graduate student at the University of North Carolina at Chapel Hill. (Nature) (ABC News)

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March anniversaries

7 March 2009 – The Kepler space telescope is launched by NASA to discover Earth-like planets orbiting other stars
13 March 1781 – William Herschel observes Uranus, which he initially believes to be a comet, eventually leading to Uranus being identified as a planet
14 March 1986 – The European robotic spacecraft Giotto becomes the first satellite to observe a comet up close when it flies through and photographs Halley's Comet
16 March 1926 – Using a mixture of gasoline and liquid oxygen, Robert H. Goddard launches the first liquid-fueled rocket
18 March 2011 – MESSENGER becomes the first spacecraft to orbit around the planet Mercury
23 March 1912 – Wernher von Braun, a German-American aerospace engineer and space architect is born

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Space-related Portals

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Astronomical events

All times UT unless otherwise specified.

1 March, 04:02	Moon occults Mercury
1 March, 21:18	Moon at perigee
8 March, 05:59	Mercury at greatest eastern elongation
12 March, 10:03	Saturn at conjunction
14 March, 06:59	Full moon and total lunar eclipse
17 March, 16:37	Moon at apogee
19 March, 22:20	Neptune at conjunction
20 March, 09:02	Earth northward equinox
23 March, 01:26	Venus at inferior conjunction
24 March, 19:27	Mercury at inferior conjunction
29 March, 10:49	New moon and partial solar eclipse
30 March, 05:26	Moon at perigee