Wikipedia:Main Page/test
![]() | This page is currently inactive and is retained for historical reference. Either the page is no longer relevant or consensus on its purpose has become unclear. To revive discussion, seek broader input via a forum such as the village pump. |
Welcome to Wikipedia, a free encyclopedia that anyone can edit.
In this English version, started in 2001, we are currently working on 6,969,287 articles.
Browse: Culture | Geography | History | Life | Mathematics | Science | Society | Technology
Browse Wikipedia - Article overviews - Alphabetical index - Other category schemes
Today's featured article![]() The Sun, viewed through a clear solar filter The Sun is the star at the center of the Solar System. It is a nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating energy from its surface mainly as light and infrared radiation. It is a G-type main-sequence star (G2V), informally called a yellow dwarf, though its light is actually white. It formed about 4.6 billion years ago and is by far the most important source of energy for life on Earth. From Earth the Sun is 1 astronomical unit (1.496×108 km) or about 8 light-minutes away. Its diameter is about 1,391,400 km (864,600 mi), 109 times that of Earth. Its mass is about 330,000 times that of Earth, making up about 99.86% of the total mass of the Solar System. Every second, the Sun fuses about 600 billion kilograms (kg) of hydrogen into helium and converts 4 billion kg of matter into energy. Venerated in many cultures, it is a central subject for astronomical research since antiquity. (This article is part of a featured topic: Solar System.)
Recently featured:
Selected anniversaries
|
In the news
Did you know...
|
Wikipedia in other languages
You can read articles in many different languages:
This Wikipedia is written in English. Many other Wikipedias are available; some of the largest are listed below.
-
1,000,000+ articles
-
250,000+ articles
-
50,000+ articles
Wikipedia's sister projects
Wikipedia is written by volunteer editors and hosted by the Wikimedia Foundation, a non-profit organization that also hosts a range of other volunteer projects:
-
Commons
Free media repository -
MediaWiki
Wiki software development -
Meta-Wiki
Wikimedia project coordination -
Wikibooks
Free textbooks and manuals -
Wikidata
Free knowledge base -
Wikinews
Free-content news -
Wikiquote
Collection of quotations -
Wikisource
Free-content library -
Wikispecies
Directory of species -
Wikiversity
Free learning tools -
Wikivoyage
Free travel guide -
Wiktionary
Dictionary and thesaurus
If you find this encyclopedia or its sister projects useful, please consider making a donation.