Jump to content

Portal:Astronomy

From Wikipedia, the free encyclopedia
The Astronomy Portal

Introduction

A man sitting on a chair mounted to a moving platform, staring through a large telescope.
Percival Lowell observing Venus from the Lowell Observatory telescope in 1914

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...)

The following are images from various astronomy-related articles on Wikipedia.

Featured article - show another

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

Known objects in the Kuiper belt beyond the orbit of Neptune. (Scale in AU; epoch as of January 2015.)
  Sun
  Jupiter trojans
  Giant planets:
  Centaurs
  Neptune trojans
  Resonant Kuiper belt
  Classical Kuiper belt
  Scattered disc
Distances but not sizes are to scale. The yellow disk is about the size of Mars' orbit.
Source: Minor Planet Center, www.cfeps.net and others

The Kuiper belt (/ˈkpər/ 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...)

More Did you know (auto generated)

WikiProjects

Selected image - show another

Credit: NASA / ESA / STScI

HD 28527 is a star in the constellation Taurus, and a member of the Hyades open cluster. It is faintly visible to the naked eye with an apparent visual magnitude of 4.78. The distance to this star, as determined from its parallax shift of 22 mas, is 148 light years.

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)
15 July 2024 – Mare Tranquillitatis pit
In the journal Nature Astronomy, American and Italian scientists announce the discovery of a lunar cave, approximately 250 miles (400 km) from the landing site of Apollo 11. (AP) (Nature Astronomy)

December anniversaries

  • 7 December 1972 – The Blue Marble photograph is taken by the Apollo 17 crew
  • 8 December 1992 – Galileo completes the second Earth flyby
  • 14 December 1962 – Mariner 2 becomes the first space probe to perform a flyby of a planet, when it passes within 35,000 kilometers of Venus
  • 17 December 1917 – 2001: A Space Odyssey science fiction author Arthur C. Clarke is born
  • 19 December 2013 – Gaia is launched for the mission to study billions of stars in the Milky Way
  • 21 December 1968 – Apollo 8, is launched with the first crewed spacecraft to leave Earth orbit, reach the Moon, orbit it, and return safely to Earth
  • 27 December 1571 – Astronomer, mathematician, and astrologer Johannes Kepler is born

Astronomical events

All times UT unless otherwise specified.

1 December, 06:21 New moon
6 December, 02:11 Mercury at inferior conjunction
7 December, 20:19 Jupiter at opposition
8 December, 08:56 Moon occults Saturn
9 December, 09:19 Moon occults Neptune
12 December, 13:18 Moon at perigee
14 December, 01:12 Geminids peak
15 December, 09:02 Full moon
18 December, 08:49 Moon occults Mars
21 December, 09:20 Earth southern solstice
22 December, 10:00 Ursids peak
24 December, 07:25 Moon at apogee
25 December, 01:59 Mercury at greatest western elongation
30 December, 22:27 New moon

Topics

Subcategories

Select [►] to view subcategories

Things you can do

Here are some Open Tasks :

Astronomy featured article candidates:

  • No current candidates

Astronomy articles for which peer review has been requested:

  • No current requests

Wikibooks

Wikibooks logo
Wikibooks logo

These books may be in various stages of development. See also the related Science and Mathematics bookshelves.

Wikijunior

Associated Wikimedia

The following Wikimedia Foundation sister projects provide more on this subject: