A cenote is a natural phenomenon, a sinkhole in the Earth’s surface. The Yucatan Peninsula in Mexico has an estimated 7,000 cenotes because it is primarily made up of porous limestone. For millions of years, rainfall slowly ate away at the limestone and a huge system of underground caves and caverns was formed. Many filled with water from rain or from the underground water table. When the roof of a water filled cave collapses, a cenote is born. The water found in a cenote may be fresh water, salt water, or both. Structurally it may be completely open, like a lake, almost completely closed with just a small opening at the top, or somewhere in between.

The Royal Observatory just announced its Astronomy Photographer Of The Year 2013 winners. Australian photographer Mark Gee was chosen among a thousand amateur and professional photographers around the globe to win the top title. His work is part of an exhibition of the winning photographers, which opened on Sept. 19 at the Royal Observatory Greenwich. The Royal Observatory shared with us the winners and notable mentions of the competition. Their descriptions of the prizewinners can be found below the images.

A fog bow is a similar phenomenon to a rainbow; however, as its name suggests, it appears as a bow in fog rather than rain. Because of the very small size of water droplets that cause fog—smaller than 0.05 millimeters (0.0020 in)—the fog bow has only very weak colors, with a red outer edge and bluish inner edge.

The Royal Observatory just announced its Astronomy Photographer Of The Year 2013 winners. Australian photographer Mark Gee was chosen among a thousand amateur and professional photographers around the globe to win the top title. His work is part of an exhibition of the winning photographers, which opened on Sept. 19 at the Royal Observatory Greenwich. The Royal Observatory shared with us the winners and notable mentions of the competition. Their descriptions of the prizewinners can be found below the images.

Lake Louise, named Lake of the Little Fishes by the Stoney Natoka First Nations people, is a glacial lake within Banff National Park in Alberta, Canada. It is located 5 km (3.1 mi) west of the Hamlet of Lake Louise and the Trans-Canada Highway (Highway 1).

The Stone Forest or Shilin is a notable set of limestone formations located in Shilin Yi Autonomous County, Yunnan Province, People's Republic of China, near Shilin approximately 120 km (75 mi) from the provincial capital Kunming. The tall rocks seem to emanate from the ground in the manner of stalagmites, with many looking like petrified trees thereby creating the illusion of a forest made of stone. Since 2007, two parts of the site, the Naigu Stone Forest (乃古石林) and Suogeyi Village (所各邑村), have been UNESCO World Heritage Sites as part of the South China Karst.

Karim Nafatni is an Airline Captain and photography enthusiast. He seriously got into the Art when he got his first DSLR 3 years ago. Addicted to height and fan of architecture,he climbs the highest skyscrapers of Dubai to take his pictures ,sometimes more than 300 meters above ground. As the top of the biggest buildings in the world is not high enough for him,he carries his camera with him during work to document his daily routine in"his Office" and shoots from his flight deck.

Thomas Barbèy grew up in Geneva, Switzerland, across the street from the “Caran D'ache” factory, the largest manufacturer of art supplies. He started drawing seriously at the age of 13, using black “encre de Chine” and gouaches for color. His influences were Philippe Druillet, Roger Dean and H.R. Giger. After living in Geneva for 17 years and designing posters for musical bands, he decided to move to Italy, where he lived in Milan for 15 years making a living as a successful recording artist, lyricist and fashion photographer.