Soldiers are reflected in a puddle during a military parade during the celebrations for Romania's National Day in Bucharest December 1, 2014. (Photo by Radu Sigheti/Reuters)

Pedestrians cover their face as they walk along the dusty road in Kathmandu, Nepal February 27, 2017. Nepal has forced 2,500 old vehicles off roads in its capital city of Kathmandu, part of a fight against alarming air pollution levels that have hit nine times World Health Organisation (WHO) limits. Air pollution has been a chronic problem in rapidly growing Kathmandu, which sits in a Himalayan valley and is home to more than 3mn people. (Photo by Navesh Chitrakar/Reuters)

A man walks on a bridge crossing over the Besor stream on a rainy day, near Kibbutz Tze'elim in Israel's southern Negev desert February 16, 2017. (Photo by Amir Cohen/Reuters)

A woman dressed in a traditional Ukrainian embroidered shirt holds her cat as she take part in an embroidered shirt parade in central Kiev, Ukraine, May 27, 2017. (Photo by Gleb Garanich/Reuters)

People walk on the street in Samara, Russia on July 18, 2017. (Photo by David Mdzinarishvili/Reuters)

A participant of “Bread Procession of the Saint”, takes part in the ceremony in honor of Domingo de La Calzada Saint (1019-1109) who helped poor people and pilgrimage, in Santo Domingo de La Calzada, northern Spain, Wednesday, May 11, 2016. Every year during spring season, “Las Doncellas” (White Virgins), hold on their head a basket cover with white cloth while they walk past along of this old village in honor of the saint. (Photo by Alvaro Barrientos/AP Photo)

People visit the artwork titled Seven Magic Mountains by artist Ugo Rondinone, Wednesday, May 11, 2016, near Jean, Nev. The artwork was recently completed in the desert south of Las Vegas. (Photo by John Locher/AP Photo)

European Space Agency astronaut Tim Peake will return home after a six-month long mission on the International Space Station,on June 18, 2016. Peake was the first British ESA astronaut to visit the ISS and captured hundreds of photographs of the Earth during his mission. Here: “Lots of sun-glint right now during our whole orbit – we haven't seen a sunset for over 3 days”, he wrote. (Photo by Tim Peake/ESA/NASA)