The Solar Impulse 2 airplane, flown by test pilot Markus Scherdel, flies off the coast of Oahu during a test flight from Kalaealoa Airfield in Kapolei, Hawaii, March 3, 2016. The solar-powered plane is ready to continue its revolutionary voyage around the world. After the craft was grounded in Hawaii last July due to overheated batteries, it was repaired and upgraded, and a recent initial test flight proved successful. (Photo by Eugene Tanner/Reuters)

“A Little Monkey on the Cliff”. “A cold front hit the Nagano prefecture. I saw a little monkey enduring the cold in Jigokudani Monkey Park. This little monkey is really cute”. (Photo by Hidetoshi Ogata/Smithsonian Photo Contest)

People walk during a polluted day in Shenyang, Liaoning province, March 31, 2016. (Photo by Reuters/Stringer)

In this May 1, 2016 photo, a reluctant donkey is alternately pushed and pulled and enticed with carrots toward town hall in order to be dressed for the costume competition at the annual donkey festival in Otumba, Mexico state, Mexico. Otumba was an important donkey market during Spanish colonial times, standing at the crossroads of major roads leading to Mexico City, where the beasts pulled heavy loads and carried travelers. Today, however, farmers use tractors and pickup trucks, and the donkey population is in decline. (Photo by Rebecca Blackwell/AP Photo)

A woman and a girl dressed in historical Red Army uniform, wait before watching the Victory Day parade, marking the 71st anniversary of the victory over Nazi Germany in World War Two, at Red Square in Moscow, Russia, May 9, 2016. (Photo by Grigory Dukor/Reuters)

Marani Devi Chaudhary (C), aged 40, performs a ritual in front of shaman Paltan Yadav (unseen) at her home in Rajaur village in Dhanusha district, Nepal, 02 November 2017. The shaman identified Marani Devi to be possessed by their lineage god who was dissatisfied by their worship is thought by the family to have caused them misfortune and is even feared lead to their death. (Photo by Narendra Shrestha/EPA/EFE)

A so-called “Supermoon” dominates the sky while traffic rolls in the streets in Naypyitaw, Myanmar, 03 December 2017. According to the National Aeronautics and Space Administration (NASA) a series of three “Supermoons” – dubbed the “Supermoon trilogy” – will appear in the sky on 03 December 2017, on 01 January 2018 and and 31 January 2018. A “Supermoon” commonly is a full moon at its closest distance to the earth with the moon appearing larger than usual. (Photo by Hein Htet/EPA/EFE)

In this picture taken on December 13, 2017, a woman commutes on a street on a cold day in Baoding. As temperatures dipped below freezing in a northern Chinese village, a group of parka-clad women tried to stay warm as they played mahjong around a small gas stove in a grocery store. (Photo by Fred Dufour/AFP Photo)