Performers line up during the closing ceremony of the 2014 Winter Olympics, Sunday, February 23, 2014, in Sochi, Russia. (Photo by Darron Cummings/AP Photo)

The competition, which is run by the Royal Observatory Greenwich in association with BBC Sky at Night Magazine, is now in its sixth year and has received over 2,500 entries. Photo: Centre of the Heart Nebula by Ivan Eder (Hungary). Situated 7500 light years away in the “W”-shaped constellation of Cassiopeia, the Heart Nebula is a vast region of glowing gas, energized by a cluster of young stars at its centre. The image depicts the central region, where dust clouds are being eroded and moulded into rugged shapes by the searing cosmic radiation. (Photo by Ivan Eder)

Now celebrating its 40th year, Nikon Small World is widely regarded as the leading forum to recognize proficiency and photographic excellence of photography taken under the microscope. To select the winners, competition judges analyzed entries from all over the world covering subjects ranging from chemical compounds to up-close-and-personal looks at biological specimens. The 2014 winners will be revealed on October 30th. In 2014, the competition received over 1,200 entries from more than 79 countries around the world. (Photo by Dr. Igor Robert Siwanowicz/Nikon Small World 2014)

An artwork entitled “Are you still mad at me?” by John Isaacs is displayed at the Death: A Self-portrait exhibition at the Wellcome Collection on November 14, 2012 in London, England. The exhibition showcases 300 works from a unique collection by Richard Harris, a former antique print dealer from Chicago, devoted to the iconography of death. The display highlights art works, historical artifacts, anatomical illustrations and ephemera from around the world and opens on November 15, 2012 until February 24, 2013. (Photo by Peter Macdiarmid)

Models walk down the runway during the Robb & Lulu swimwear show as part of Funkshion Fashion Week Swim, Friday, July 17, 2015, in Coral Gables, Fla. (Photo by Lynne Sladky/AP Photo)

In this photo taken on Thursday, July 23, 2015 migrants enter a train to Serbia at the railway station in the southern Macedonian town of Gevgelija. The country has become a major transit route for thousands of Middle Eastern and African refugees and migrants who cross over from Greece and then continue into Serbia. (Photo by Boris Grdanoski/AP Photo)

A koala soaked by floodwaters sits atop a fence post to escape the deluge in the town of Stirling in the Adelaide Hills of South Australia in this picture taken September 14, 2016. (Photo by Russell Latter/Reuters)

Goats wait to get unloaded from a vehicle at a livestock market during Dashain, the biggest religious festival for Hindus in Nepal, in Kathmandu, Nepal October 4, 2016. (Photo by Navesh Chitrakar/Reuters)