68 (number) - Definition and Overview

68 is the natural number following 67 and preceding 69

In mathematics

Sixty-eight is a nontotient.

In science

• The atomic number of erbium, a lanthanide

In astronomy,

Messier object M68, a magnitude 9.0 globular cluster in the constellation Hydra

The New General Catalogue object (http://www.ngcic.org/) NGC 68, a spiral galaxy in the constellation Andromeda

The Saros number (http://sunearth.gsfc.nasa.gov/eclipse/SEsaros/SEsaros1-175.html) of the solar eclipse series which began on -626 March 16 and ended on 685 August 20. The duration of Saros series 68 was 1280.1 years, and it contained 72 solar eclipses.

The Saros number (http://sunearth.gsfc.nasa.gov/eclipse/LEsaros/LEsaros1-175.html) of the lunar eclipse series which began on -613 July 3 and ended on 685 August 20. The duration of Saros series 68 was 1298.1 years, and it contained 73 lunar eclipses.

In other fields

• In degrees Celsius, the ideal temperature for developing black-and-white film.
• The designation of US Interstate 68, a freeway that runs from West Virginia to Maryland.
• The registry of the U.S. Navy's aircraft carrier USS Nimitz (CVN-68), named after Admiral Chester Nimitz.
• The number of the French department Haut-Rhin.
• The year AD 68, 68 BC, or 1968.