Sandra, a 29-year-old orangutan at Buenos Aires' zoo, on May 20, 2015. Sandra got cleared to leave a Buenos Aires zoo that was her home for 20 years, after a court ruled she was entitled to more desirable living conditions. (Photo by Juan Mabromata/AFP Photo)

A Fulton Hotshot lights a controlled burn on the so-called “Rough Fire” in the Sequoia National Forest, California, August 21, 2015. In California, suffering its worst drought on record, about 2,500 people were forced to flee Christian camps east of Fresno at Hume Lake as the so-called Rough Fire crossed Highway 180, officials said. (Photo by Max Whittaker/Reuters)

In this photo taken on Monday, January 5, 2015, a mallard duck attempts to walk on a frozen pond in Yukon, Okla. (Photo by Steve Gooch/AP Photo/The Oklahoman)

This picture was taken in the 1890's and shows a group of loggers hauling a heavy load. It is hard to even picture how they got the logs stacked that high. It is also hard to imagine how they keep it from tipping over.

A seagull who turned bright orange after he plunged into a vat of chicken tikka masala in Beckford, England on June 9, 2016. The bird fell into a container of the food while trying to scavenge a piece of meat from a food factory bin in Wales. (Photo by Vale Wildlife Hospital/PA Wire)

Thailand’s Sanctuary of Truth is an all-wood building filled with sculptures based on traditional Buddhist and Hindu motifs. It is covered in intricate wood carvings, meant to depict complex ideas about ancient thought, human responsibility, and the cycle of life. (Photo by Yury Taranik/Getty Inages)

Spain's Lidia Rodriguez, Spain's Marta Garcia and Spain's Raquel Roy compete in the Kata team female final during the 24th Karate World Championships at the WiZink center in Madrid on November 11, 2018. (Photo by Javier Soriano/AFP Photo)

The competition is run by Royal Observatory Greenwich sponsored by Insight Investment and in association with BBC Sky at Night Magazine. This year astrophotographers from 91 countries sent in more than 4,200 spectacular entries. Here: The Milky Way rises above an isolated lighthouse in Tasmania. Shot by James Stone of Australia. (Photo by James Stone/Astronomy Photographer of the Year 2018)