A masked reveller poses along the flooded St. Mark's Square during a period of seasonal high water and on the first day of carnival, in Venice February 1, 2015. (Photo by Stefano Rellandini/Reuters)
Masked revellers pose in St. Mark's Square during the Venice Carnival, February 7, 2015. The Venetian carnival started on January 31 and runs until February 17, forty days before Easter celebrations. (Photo by Stefano Rellandini/Reuters)
Schick Hydro and Chanel Iman get guys #NakedFaced at the Schick Hydro Barbershop at The Sports Illustrated Swim City Event on February 9, 2015 in New York City. (Photo by Ilya S. Savenok/Getty Images for Schick)
Richard Kilty of Britain celebrates after winning the men's 60 metres final during the European Indoor Championships in Prague March 8, 2015. REUTERS/David W Cerny (CZECH REPUBLIC - Tags: SPORT ATHLETICS)
Elephants spray tourists with water in celebration of the Songkran water festival in Thailand's Ayutthaya province, about 80 km (50 miles) north of Bangkok, April 9, 2014. (Photo by Rungroj Yongrit/EFE)
Colored Pencil and Origami Landscapes: Ivanova's version of the popular Snake game features a chain-link origami snake chasing a butterfly. (Photo by Victoria Ivanova)
A female member of the Ahbab Al-Mustafa Battalion holds a gun as she undergoes military training in Aleppo's Salaheddine district, June 24, 2013. (Photo by Muzaffar Salman/Reuters)
Our moon is a pretty big object. It's big enough to be a respectable planet in its own right, if it were orbiting the sun instead of the Earth. (Actually, it is orbiting the sun in a nearly perfectly circular orbit, that the Earth only slightly perturbs... but that's a topic for another day.) The Moon is a quarter the diameter of the Earth. Only Pluto has a satellite that is larger, in proportion to the size of the planet it orbits.