Participants struggle to reach the prizes during a greased-pole climbing competition held as a part of the independence day celebrations in Jakarta, Indonesia, Sunday, August 17, 2014. Indonesia is celebrating its 69th independence from the Dutch colonial rule. (Photo by Dita Alangkara/AP Photo)

October winner. “A burst of the aurora borealis over Kirkjufell, taken in September 2016. This shot has been a holy grail for me and was finally captured after many trips”. MICK RYAN, JUDGE: Iceland is a hotspot for aurora photography and this composition of the symmetric, free-standing Kirkjufell and the trident waterfall is much-sought after. If you can time your visit when the aurora “kp” index is high and know the settings for nighttime aurora images, you may end up with a beautiful photograph like this. (Photo by DВ/The Guardian)

Spanish runner Francisco Contreras, 77, known as “Super Paco”, runs as he participates in the XVIII 101km international competition in the outskirts of Ronda, southern Spain, May 9, 2015. About 7,000 participants, including runners, mountain bikers and duathletes, run a track of 101 km (63 miles) in less than 24 hours through the “Serrania de Ronda” (Ronda Mountain Range) during this competition organised by the 4th Tercio (Regiment) “Alejandro Farnesio” of the Spanish Legion. The Puente Nuevo is 120 metres (394 feet) high over the gorge of the river that divides the city of Ronda. Picture taken using long exposure. (Photo by Jon Nazca/Reuters)

Taking it all in at Trolltunga, a piece of rock which juts horizontally out of a mountain, 700 metres above lake Ringedalsvatnet in Norway. (Photo by Sam Rogers/GuardianWitness)

“After an afternoon of hiking and exploring the caves of Rhossili Bay, West Glamorgan, we caught the sun breaking through the clouds”. (Photo by Megan Warren-Davis/The Guardian)

A competitor jumps from the Old Bridge during Red Bull Cliff Diving Competition in Mostar, Bosnia and Herzegovina on August 15, 2015. (Photo by Dado Ruvic/Reuters)

Most people know Nikon as a purveyor of pro and consumer-grade digital cameras. But the company's expertise with optics bleeds over into related markets – it's one of the science community's major suppliers of microscopes. And each year the company asks the community to send it some of their favorite images of tiny objects. A panel of scientists and journalists have chosen the best of this past year's submissions, which Nikon has placed on its Small World site.

Photo: Honorable Mention. “Snow crystal, illuminated with colored lights (5x)”. (Photo by Dr. Kenneth Libbrecht, California Institute of Technology (Caltech), Department of Physics, Pasadena, California, USA)

An iguana in Bali helped Julij Kopilović, age eight, from Slovenia, earn second runner-up in Amazing Animals. (Photo by Julij Kopilović/National Geographic)