Equinox

An equinox is an astronomical event in which the plane of Earth's equator passes through the center of the Sun, making night and day of approximately equal length all over the planet. An equinox occurs twice each year, around 21 March and 23 September.

The equinoxes are the only times when the solar terminator (the "edge" between night and day) is perpendicular to the equator. As a result, the northern and southern hemispheres are equally illuminated.

In other words, the equinoxes are the only times when the subsolar point is on the equator, meaning that the Sun is exactly overhead at a point on the equatorial line. The subsolar point crosses the equator moving northward at the March equinox and southward at the September equinox.

The equinoxes, along with solstices, are directly related to the seasons of the year. In the northern hemisphere, the vernal equinox (March) conventionally marks the beginning of spring in most cultures and is considered the New Year in the Persian calendar, while the autumnal equinox (September) marks the beginning of autumn. In the southern hemisphere, the vernal equinox occurs in September and the autumnal equinox in March.

National Geographic

National Geographic or NatGeo may refer to:

See also

First Day

First Day may refer to:

September 22

September 22 is the 265th day of the year (266th in leap years) in the Gregorian calendar. There are 100 days remaining until the end of the year.
It is frequently the day of the autumnal equinox in the Northern Hemisphere and the day of the vernal equinox in the Southern Hemisphere.

Events

Google Doodle

A Google Doodle is a special, temporary alteration of the logo on Google's homepage that is intended to celebrate holidays, events, achievements and people. The first Google Doodle was in honor of the Burning Man Festival of 1998, and was designed by Larry Page and Sergey Brin to notify users of their absence in case the servers crashed. Subsequent Google Doodles were designed by an outside contractor, until Page and Brin asked intern Dennis Hwang to design a logo for Bastille Day in 2000. From that point onward, Doodles have been organized and published by a team of employees termed "Doodlers".

Initially, Doodles were neither animated nor hyperlinked. Doodles increased in both frequency and complexity by the beginning of the 2010s, and in January 2010 the first animated Doodle was posted honoring Isaac Newton. The first interactive Doodle appeared shortly thereafter celebrating Pac-Man, and hyperlinks also began to be added to Doodles, usually linking to a search results page for the subject of the Doodle. As of 2014, Google has published over 2,000 regional and international Doodles throughout its homepages, often featuring guest artists, musicians and personalities.