A man poses standing on a rock looking at the aurora borealis, or northern lights, illuminating the night sky at Embleton Bay in Northumberland, England, on February 27, 2014. The northern lights is a fantastical natural light display with fast moving light effects caused by particles charged by the sun colliding with particles in Earth's upper atmosphere. (Photo by Tom White/PA Wire)

Mount Sinabung, a highly active volcano on Sumatra island, erupted several times this week. A volcanology agency has declared a danger zone of about four miles from the crater after seven farmers were killed and two others seriously injured. Here: A man carries his dog as a giant ash cloud rises from the Sinabung volcano in Karo, Indonesia on May 26, 2016. (Photo by Sutanta Aditya/Barcroft Images)

A crocodile at a zoo in the southern Taiwan city of Kaohsiung holds the forearm of a zoo veterinarian in its teeth, April 2007. Surgeons in Taiwan have reattached a vet's arm, after it was bitten off by a crocodile as he tried to give it an anaesthetic injection. His attacker is one of a pair of Nile crocodiles kept at Shoushan zoo. Nile crocodiles are known to be man-eaters, but are also listed as an endangered species. (Photo by Frank Lin/Reuters)

A man holds a child after rescuing him from a kindergarten affected by a fire at a commercial building, in Ningde, Fujian province, China, September 16, 2015. According to local media, more than 260 people were evacuated due to the fire, which broke out Wednesday morning. No causalities have been reported and the cause of it is still unknown. (Photo by Reuters/China Daily)

A Thai man climbs down from his home in a disused airplane on September 12, 2015 in Bangkok, Thailand. 3 impoverished Thai families have begun living in disused airplanes on a private field. The families, who collect and recycle garbage earning a few dollars a day, can't afford to rent and prefer to stay in the planes. (Photo by Taylor Weidman/Getty Images)

(L-R) A man nicknamed "Barcelona", Alexey Bolotov and Alexey Jakushin drink vodka as they travel by a pioneer motorised railcar on their way to Kalach, Sverdlovsk region, Russia October 18, 2015. The "pioneer," a light auxiliary rail vehicle, is a popular form of transport among people who live along the Alapayevsk railway. In a remote corner of the Urals region at the end of a narrow-gauge railway is Kalach, population about a dozen. Three decades ago 600 people called the village home, but the local forestry industry suffered as the former Soviet Union imploded and people moved away in search of work. In Kalach today there are no telephones, no mobile reception and only a few hours of electricity a day. (Photo by Maxim Zmeyev/Reuters)

M42 Subtle V1 cropped. One of the most well-known astronomical objects in our universe is the Orion Nebula and this image depicts the wider region of the Orion Molecular Cloud Complex that is its home. This complex also includes another popular target for astrophotographers, the Horsehead Nebula, as well as Barnard’s Loop and the Running Man Nebula, which can be seen to the left of this photograph. (Photo by Patrick Gilliland)

A man carries a dog and wades through a flooded street in Chennai, in the southern Indian state of Tamil Nadu, Wednesday, December 2, 2015. Weeks of torrential rains have forced the airport in the state capital Chennai to close and have cut off several roads and highways, leaving tens of thousands of people stranded in their homes, government officials said Wednesday. (Photo by AP Photo)