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, literally meaning the science that studies the laws of the stars) 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, 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.

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...)

Cscr-featured.png Featured article - show another

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

Location of Tau Ceti

Tau Ceti, Latinized from τ Ceti, is a single star in the constellation Cetus that is spectrally similar to the Sun, although it has only about 78% of the Sun's mass. At a distance of just under 12 light-years (3.7 parsecs) from the Solar System, it is a relatively nearby star and the closest solitary G-class star. The star appears stable, with little stellar variation, and is metal-deficient.

Observations have detected more than ten times as much dust surrounding Tau Ceti as is present in the Solar System. Since December 2012, there has been evidence of at least four planets—all confirmed being super-Earths—orbiting Tau Ceti, with two of these being potentially in the habitable zone. There are an additional four unconfirmed planets, one of which is a Jovian planet between 3 and 20 AU from the star. Because of its debris disk, any planet orbiting Tau Ceti would face far more impact events than Earth. Despite this hurdle to habitability, its solar analog (Sun-like) characteristics have led to widespread interest in the star. Given its stability, similarity and relative proximity to the Sun, Tau Ceti is consistently listed as a target for the Search for Extra-Terrestrial Intelligence (SETI) and appears in some science fiction literature. (Full article...)

Subcategories

Category puzzle
Select [►] to view subcategories

WikiProjects

Selected image - show another

NGC 1300
Credit: NASA, ESA, and The Hubble Heritage Team STScI/AURA

NGC 1300 is a barred spiral galaxy about 61 million light-years away in the constellation Eridanus. The galaxy is about 110,000 light-years across; just slightly larger than our own galaxy, the Milky Way.

Astronomy News

The time allocated for running scripts has expired.

The time allocated for running scripts has expired.

The time allocated for running scripts has expired.

The time allocated for running scripts has expired.

Wikibooks logo

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

Wikijunior

The time allocated for running scripts has expired. All times UT unless otherwise specified.

2 January, 08:59 Earth at perihelion
3 January, 14:47 Quadrantids peak
9 January, 15:39 Moon at perigee
13 January, 05:00 New moon
21 January, 13:11 Moon at apogee
24 January, 01:59 Mercury at greatest eastern elongation
24 January, 02:26 Saturn at conjunction
28 January, 19:16 Full moon
29 January, 00:51 Jupiter at conjunction

The time allocated for running scripts has expired.

The time allocated for running scripts has expired. The time allocated for running scripts has expired.

The time allocated for running scripts has expired.

Here are some Open Tasks :

Astronomy featured article candidates:

  • No current candidates

Astronomy articles for which peer review has been requested:

  • No current requests

The time allocated for running scripts has expired.

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

Portals

The time allocated for running scripts has expired. The time allocated for running scripts has expired. The time allocated for running scripts has expired. The time allocated for running scripts has expired. The time allocated for running scripts has expired. The time allocated for running scripts has expired. The time allocated for running scripts has expired. The time allocated for running scripts has expired. The time allocated for running scripts has expired. The time allocated for running scripts has expired. The time allocated for running scripts has expired. The time allocated for running scripts has expired. The time allocated for running scripts has expired.

Purge server cache