Mardi Gras 2012, or Fat Tuesday, falls on Feb. 21, and is the final day of the festivities known as Carnival. Mardi Gras is celebrated in predominately Catholic locations around the world, most famously in cities such as New Orleans and Rio de Jainaro. While best known for parties, costumes and beads, Mardi Gras has religious origins in the Catholic calendar as well as in pre-Christian pagan celebrations.
The Latin root of the word Carnival is carne vale, which means "farewell to meat" -- a reference to the upcoming 40 day fast of Lent that commences at midnight on Mardi Gras. Fat Tuesday was named because it was a time of extravagant feasting of rich foods such as meat or pancakes before the upcoming fast. According the Catholic calendar, the season of Carnival actually starts on the 12th day of Christmas, known as Epiphany. And in Germany, where Carnival is known as Fasching, festivities start on Epiphany and build toward Mardi Gras.
Fat Tuesday is also know as Shrove Tuesday, a reference to "shriving" or confession, which was meant to prepare Christians for the fast ahead. Some communities use Shrove Tuesday to burn palm fronds from the previous year's Palm Sunday to create the ashes that are used on Ash Wednesday. Ash Wednesday is the fist day of the season of penitance and fasting that leads to Good Friday and Easter. Ash Wednesday is a solemn observance when many Christians receive ashes on the foreheads and are reminded that "they are dust and to dust they shall return."