The Solar System is the gravitationally bound system of the Sun and the objects that orbit it. There are eight planets, numerous dwarf planets, the asteroid belt between Mars and Jupiter, the Kuiper belt, and the scattered disc beyond Neptune's orbit. The Solar System was formed 4.6 billion years ago from the gravitational collapse of an interstellar molecular cloud, which formed the Sun and a protoplanetary disk that coalesced into other objects. Many celestial bodies have natural satellites orbiting them, and all giant planets and a few smaller bodies are encircled by planetary rings. Many small-body populations, including comets, centaurs, and interplanetary dust clouds, freely travel between the Solar System's regions. The solar wind, a stream of charged particles flowing outwards from the Sun, creates a heliosphere region. The Oort cloud may extend roughly a thousand times farther than the heliosphere. (This article is part of a featured topic: Solar System.).

Read more: https://en.wikipedia.org/wiki/Wikipedia:Featured_topics/Solar_System

_______________________________ Today's selected anniversaries:

1960:

A C-46 airliner carrying the Cal Poly Mustangs football team crashed during takeoff from Toledo Express Airport in Ohio, U.S., resulting in 22 deaths. https://en.wikipedia.org/wiki/California_Polytechnic_State_University_football_team_plane_crash

1986:

British prime minister Margaret Thatcher officially opened the M25, one of Britain's busiest motorways. https://en.wikipedia.org/wiki/M25_motorway

1991:

Galileo became the first spacecraft to visit an asteroid when it made a flyby of 951 Gaspra. https://en.wikipedia.org/wiki/951_Gaspra

2013:

The first phase of the Marmaray project opened with an undersea rail tunnel (train pictured) across the Bosphorus strait. https://en.wikipedia.org/wiki/Marmaray

_____________________________ Wiktionary's word of the day:

asterisk: 1. (dated) A small star; also (by extension), something resembling or shaped like a star. 2. The star-shaped symbol *, which is used in printing and writing for various purposes, including to refer a reader to a note at the bottom of a page or in a margin, and to indicate the omission of letters or words; a star. 3. Something resembling or shaped like an asterisk symbol. 4. (figuratively) Something which is of little importance or which is marginal; a footnote. 5. (US, sports, figuratively) A blemish in an otherwise outstanding achievement. 6. (Eastern Orthodoxy, Roman Catholicism) An instrument with radiating arms resembling a star which is placed over the diskos (or paten) used during the Eucharist to prevent the veil covering the chalice and diskos from touching the host on the diskos. 7. (transitive) To mark or replace (text, etc.) with an asterisk symbol (*; noun sense 1.1); to star. https://en.wiktionary.org/wiki/asterisk

___________________________ Wikiquote quote of the day:

The ground for taking ignorance to be restrictive of freedom is that it causes people to make choices which they would not have made if they had seen what the realization of their choices involved.   --Alfred Jules Ayer https://en.wikiquote.org/wiki/Alfred_Jules_Ayer