Today is Fat Tuesday, or Mardi Gras, that last hurrah before Ash Wednesday and the Catholic season of Lent begins.

View Photo Gallery: As many as 850,000 tourists descend on Rio de Janeiro for the five-day-long Carnival celebration.

Legions of Mardi Gras attendees in New Orleans are preparing to mark the day with revelry, beads and lots and lots of rich, fatty food. Meet Rex and the King of Zulu, the city’s 2012 Mardi Gras monarchs, at In Brazil, where the festival of Carnival has kicked off in earnest, Rio de Janeiro’s elite samba schools paraded Sunday through the city’s newly renovated Sambadrome. Watch video at The Post.

Other morning links:

Arab Spring protests of the morning

Yemen is finally voting to install a new president, but the election was marred by violence, including an attack by gunmen on polling stations. (Washington Post)

Damascus has revolted, the latest city where protests have spread as violence continues to escalate in Syria. (Guardian live blog)

YouTube footage of the morning

Bahraini police used giant water cannons and tear gas Monday on protesters marching after a funeral, the latest wave of violence in the tiny kingdom. (YouTube)

A Syrian man with learning difficulties was purportedly encouraged by pro-Assad forces to beat a detainee, as shown in a new video online. (YouTube)

Culture clash of the morning

Angry over the improper disposal of the Koran by foreign troops, thousands of Afghans protested Tuesday, with many trying to storm a U.S. base. The Koran was reportedly burned. (Washington Post)

NATO has apologized, ordering a full investigation. (BBC)

Images of the morning

— “The Nine Eyes of Google Street View,” a photo project by artist Jon Rafman, has collected weird and beautiful images from around the world, captured by Google by accident. Don’t miss the image of a man crouching in the forest in a gas mask in Montezuma, Mexico. (The Guardian)

More world news coverage:

- The man who retrieves the Taliban’s dead

- Putin promises Russian military buildup

- Greece secures second bailout deal

- Read more headlines from around the world