Jump to content

英文维基 | 中文维基 | 日文维基 | 草榴社区

Wikipedia:Main Page history/2021 May 5b

From Wikipedia, the free encyclopedia
Sun

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 the energy mainly as visible light and infrared radiation. It is by far the most important source of energy for life on Earth. Its diameter is about 1.39 million kilometres (860,000 mi), or 109 times that of Earth. Its mass is about 330,000 times that of Earth, and accounts for about 99.86 percent of the total mass of the Solar System. Roughly three-quarters of the Sun's mass consists of hydrogen; the rest is mostly helium, with much smaller quantities of heavier elements, including oxygen, carbon, neon, and iron. This diagram illustrates the general structure of the Sun, with all features drawn to scale.

Diagram credit: Kelvin Ma

Other areas of Wikipedia

  • Community portal – Bulletin board, projects, resources and activities covering a wide range of Wikipedia areas.
  • Help desk – Ask questions about using Wikipedia.
  • Local embassy – For Wikipedia-related communication in languages other than English.
  • Reference desk – Serving as virtual librarians, Wikipedia volunteers tackle your questions on a wide range of subjects.
  • Site news – Announcements, updates, articles and press releases on Wikipedia and the Wikimedia Foundation.
  • Village pump – For discussions about Wikipedia itself, including areas for technical issues and policies.

Wikipedia's sister projects

Wikipedia is hosted by the Wikimedia Foundation, a non-profit organization that also hosts a range of other projects:

Wikipedia languages