Aurora at Funchal, Madeira, Portugal on December 31, 2011. Photo © Jorge Humberto Freitas

  Aurora at Lisbon, Portugal on December 23, 2011. Photo © João Loureiro

  Aurora at Ponta Delgada, Azores, Portugal on December 15, 2011. Photo © André Moura

  Aurora at Ponta Delgada, Azores, Portugal on December 15, 2011. Photo © António Simas

  Aurora at Castries, St. Lucia on November 25, 2011. Photo © Elias Balazs

  Aurora at Funchal, Madeira on November 18, 2011. Photo © Jorge Ferreira

  Aurora at Bergen, Norway on July 22, 2011. Photo © Kjell Christian Andersens

  Aurora at Venice, Italy on May 30, 2011. Photo © Earl Gough

  Aurora at Ponta Delgada, Azores, Portugal on April 17, 2011. Photo © António Simas

  Aurora at Ponta Delgada, Azores, Portugal on April 11, 2011. Photo © António Simas

  Aurora at Sydney, Australia on March 2, 2011. Photo © Robert Winslow

  Aurora at Ponta Delgada, Azores, Portugal on January 5, 2011. Photo © António Simas

  Aurora at Funchal, Madeira, Portugal on December 20, 2010. Photo © João Abreu

  Aurora at Funchal, Madeira, Portugal on November 12, 2010. Photo © Francisco Rosendo Figueira

  Aurora at Ponta Delgada, Azores, Portugal on October 19, 2010. Photo © António Simas

  Aurora at Québec City, Canada on September 22, 2010. Photo © Eric Coulombe

  Aurora at Dublin, Ireland on June 20, 2010. Photo © Jonathan McDonnell

  Aurora at Kotor, Montenegro on June 11, 2010. Photo © Danijela Paljusic

  Aurora at Southampton, United Kingdom on June 2, 2010. Photo © Matthew Gledhill

  Aurora at Lisbon, Portugal on April 28, 2010. Photo © Rui Agostinho

  Aurora at Fremantle, Australia on March 11, 2010. Photo © Bob Prins

  Aurora at Gibraltar, United Kingdom on December 2, 2009. Photo © Giovanni Romero

  Aurora at Gibraltar, United Kingdom on November 14, 2009. Photo © Giovanni Romero

  Aurora at Venice, Italy on October 24, 2009. Photo © Christophe D'haene

  Aurora at Lisbon, Portugal on September 28, 2009. Photo © Ruí Pais

  Aurora at Argostoli, Kefalonia, Greece on July 23, 2009. Photo © Andreas Pefanis

  Aurora at Argostoli, Kefalonia, Greece on May 24, 2009. Photo © Rolf Kummer

  Aurora at Gdynia, Poland on May 8, 2009. Photo © Wlodzimierz Kociecki

  Aurora at Ponta Delgada, Azores, Portugal on April 10, 2009. Photo © António Simas

  Aurora at San Francisco, California on March 24, 2009. Photo © Jake Tomlinson

  Aurora at Sydney, Australia on March 2, 2009. Photo © Phillip Massaad

  Aurora at Funchal, Madeira, Portugal on January 8, 2008. Photo © João Abreu

  Aurora at Southampton, United Kingdom on October 18, 2008. Photo © Richard Maidment

  Aurora at sea, 600 miles off New York on September 5, 2008. Photo © Fred Claessen

  Aurora at Funchal, Madeira, Portugal on June 27, 2008. Photo © Edgar Freitas

  Aurora at Tallinn, Estonia on May 12, 2008. Photo © Roland Edström

  Aurora in the Bay of Biscay on April 19, 2008. Photo © Peter Jaggs

  Aurora at Rotterdam, Netherlands on December 8, 2007. Photo © Cees de Bijl

  Aurora at Rotterdam, Netherlands on December 8, 2007. Photo © Cees de Bijl

  Aurora at Southampton, United Kingdom on April 22, 2007. Photo © Richard Maidment

  Aurora at Geiranger, Norway on July 5, 2006. Photo © Victor Ross

  Aurora at Ny Alesund, Spitsbergen, Norway on July 1, 2006. Photo © Victor Ross

  Aurora at Split, Croatia on July 31, 2005. Photo © Robert Glebowski

  Aurora at Southampton, United Kingdom on January 11, 2004. Photo © Bart de Boer

  Aurora at Southampton, United Kingdom on January 11, 2004. Photo © Bart de Boer

  Aurora at Venice, Italy on August 24, 2002. Photo © Peter Lowe

  Aurora at Buitenhuizen, Netherlands on June 24, 2001. Photo © Bart de Boer

  Aurora at Buitenhuizen, Netherlands on June 24, 2001. Photo © Bart de Boer