A fireman pulls a woman and her dog to shore, by a row of houseboats on the river Seine in Paris France, Wednesday June 1, 2016. The Seine River has overflowed embankments in Paris as floods hit or threaten cities and towns around France. (Photo by Jerome Delay/AP Photo)

In this picture taken Thursday, August 4, 2016, seal Tristan looks out of a basket while being released into the North Sea together with others at the beach of the island Juist, Germany. He is part of the first group of released seals of the seal breeding station Norddeich this year. (Photo by Carmen Jaspersen/DPA via AP Photo)

Women perform yoga on a dried river bank in Yunyang county, Chongqing Municipality, August 21, 2016. (Photo by Reuters/China Daily)

A man wearing a mask and dressed in a clown costume rides an electric tricycle while carrying a container in the shape of a rubber duck amid heavy smog in Beijing, China, December 29, 2015. (Photo by Jason Lee/Reuters)

An Afghan teacher, in brown, helps school children run from the site of clashes near the Pakistan consulate in Jalalabad, capital of Nangarhar province, Afghanistan, Wednesday, January 13, 2016. Several members of the Afghan security forces were killed Wednesday after unidentified gunmen attacked the Pakistani consulate in a volatile eastern province, an official said on Wednesday. (Photo by Mohammad Anwar Danishyar/AP Photos)

A containment shelter for the damaged fourth reactor (L) and the New Safe Confinement (NSC) structure (R) at the Chernobyl Nuclear Power Plant are seen from Ukraine's abandoned town of Pripyat, Ukraine, April 22, 2016. (Photo by Gleb Garanich/Reuters)

Tsukimi Ayano steps out of her house in the village of Nagoro on Shikoku Island in southern Japan February 24, 2015. Tsukimi Ayano made her first scarecrow 13 years ago to frighten off birds pecking at seeds in her garden. The life-sized straw doll resembled her father, so she made more. Today, the tiny village of Nagoro in southern Japan is teeming with Ayano's hand-sewn creations, frozen in time for a tableau that captures the motions of everyday life. (Photo by Thomas Peter/Reuters)

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)