Yuri's Night is known as the "World Space Party." It is an annual event celebrated on or around April 12 of each year. April 12 marks the anniversary of both the first manned spaceflight and the first space shuttle launch. Yuri Gagarin became the first man to fly in space on April 12, 1961, when he orbited the earth once in the Vostok 1 spacecraft. Twenty years later, on April 12, 1981, the space shuttle Columbia made its maiden voyage on mission STS-1.
Yuri's Night was founded by Loretta Hidalgo, George Whitesides, and Trish Garner. The first Yuri's Night celebration was held in April 2001, in 64 locations throughout the world. Yuri's Night is a Space Generation Advisory Council event.
Yuri's Night is not just a single party, but an event in which a large number of parties are held throughout the world. As of January 2011, 65 locations in 21 countries have scheduled Yuri's Night events, with more being added frequently. Events have been held all over the world, from places such as NASA Centers to South Africa to the Amundsen-Scott South Pole Station in Antarctica. The largest Yuri's Night celebration occurs at the NASA Ames Research Center in Mountain View, CA, which attracts crowds of up to 10,000 people.
Yuri's Night parties take on a variety of flavors, from large dance parties to exhibits, festivals, and private events. A list of currently registered events is available on the official Yuri's Night website, http://www.yurisnight.net/. Anyone can create or host a Yuri's Night party.