Portal:Astronomy

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
The Astronomy Portal

Introduction

A man sitting on a chair mounted to a moving platform, staring through a large telescope.

Astronomy (from Greek: ἀστρονομία) is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, 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 outside Earth's atmosphere. Cosmology is a branch of astronomy. It 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 Babylonians, Greeks, Indians, Egyptians, Nubians, Iranians, 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. Nowadays, professional astronomy is often said to be the same as astrophysics.

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.

Amateurs play an active role in astronomy. It is one of the few sciences in which this is the case. 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.

Cscr-featured.png Featured article - show another

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

Io highest resolution true color.jpg

Io (Jupiter I) is the innermost and third-largest of the four Galilean moons of the planet Jupiter. It is the fourth-largest moon in the solar system, has the highest density of all of them, and has the lowest amount of water (by atomic ratio) of any known astronomical object in the Solar System. It was discovered in 1610 by Galileo Galilei and was named after the mythological character Io, a priestess of Hera who became one of Zeus' lovers.

With over 400 active volcanoes, Io is the most geologically active object in the Solar System. This extreme geologic activity is the result of tidal heating from friction generated within Io's interior as it is pulled between Jupiter and the other Galilean satellites—Europa, Ganymede and Callisto. Several volcanoes produce plumes of sulfur and sulfur dioxide that climb as high as 500 km (300 mi) above the surface. Io's surface is also dotted with more than 100 mountains that have been uplifted by extensive compression at the base of Io's silicate crust. Some of these peaks are taller than Mount Everest, the highest point on Earth's surface. Unlike most satellites in the outer Solar System, which are mostly composed of water ice, Io is primarily composed of silicate rock surrounding a molten iron or iron-sulfide core. Most of Io's surface is composed of extensive plains coated with sulfur and sulfur-dioxide frost. Read more...

Subcategories

Category puzzle
Select [►] to view subcategories

WikiProjects

Selected image - show another

Flaming Star Nebula
Credit: User:Hewholooks

IC 405, also Sharpless 229 (Sh2-229), Caldwell 31 and The Flaming Star Nebula, is an emission/reflection nebula and a Caldwell object in the constellation Auriga, surrounding the bluish star AE Aurigae. It shines at magnitude +6.0. The nebula is about 5 light-years across. This is a white light image of the Flaming Star Nebula showing the "smoke" of reflection nebula.

Astronomy News

7 October 2019 –
Astronomers announce the discovery of 20 new moons around Saturn, adding to the 62 previously known. The new moons comprise 17 retrograde moons in the Norse group and three prograde moons, two of which belong to the Inuit group. (Phys.org)
12 September 2019 – Interstellar objects
C/2019 Q4 (Borisov), a second interstellar comet after ʻOumuamua in 2017, is discovered by an amateur astronomer. (BBC)
19 August 2019 –
Astronomers led by a team from McGill University in Montreal announce the detection of eight new repeating fast radio bursts (FRBs) using the Canadian Hydrogen Intensity Mapping Experiment (CHIME) radio telescope. The astronomers report they also found complex morphologies and downward-drifting sub-bursts in some of the eight new FRBs. (Phys.org)
1 August 2019 – List of nearest exoplanets
Astronomers from the Max Planck Institute for Astronomy announce the discovery of red dwarf star GJ 357 and its three confirmed exoplanets in the Hydra constellation, one of which (GJ 357 d) is highly likely to be a super-Earth planet located in the system's circumstellar habitable zone where life can exist. The discovery was made using NASA's Transiting Exoplanet Survey Satellite (TESS). (The Independent)
17 July 2019 –
Astronomers rule out the chances of ~30-meter asteroid 2006 QV89's impacting Earth in September 2019 by eliminating the possibility of its passing through an area where it would have to be if it were on an impacting orbit. Prior to this, the asteroid had been given a one-in-7,000 chance of impacting Earth. (phys.org)
31 January 2019 –
Astronomers announce, through the Monthly Notices of the Royal Astronomical Society journal, the accidental discovery of dwarf spheroidal galaxy Bedin I in the Pavo constellation in September 2018. (Space Telescope)

December anniversaries

  • 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
  • 19 December 2013 - Gaia was launched. Its mission is to study billions of stars in the Milky Way
  • 21 December 1968 - Apollo 8, the first crewed spacecraft to leave Earth orbit, reach the Moon, orbit it, and return safely to Earth, is launched

Space-related Portals

Wikibooks

Astronomical events

All times UT unless otherwise specified.

5 December, 04:07 Moon at apogee
12 December, 05:12 Full moon
14 December, 16:00 Geminids peak
18 December, 20:27 Moon at perigee
22 December, 04:19 Earth southern solstice
26 December, 05:18 New moon and annular solar eclipse
26 December, 07:30 Moon occults Jupiter
27 December, 14:31 Moon occults Pluto
27 December, 18:25 Jupiter at conjunction, occultation
29 December, 01:31 Moon occults Venus

Basics

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

Associated Wikimedia

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

Wikibooks
Books

Commons
Media

Wikinews 
News

Wikiquote 
Quotations

Wikisource 
Texts

Wikiversity
Learning resources

Wiktionary 
Definitions

Wikidata 
Database