Swiss pilot Bertrand Piccard prepares for a test flight of the solar-powered Solar Impulse 2 experimental aircraft in Payerne November 13, 2014. The aircraft, weighing 2.4 tons with a wingspan of 72 meters, is fitted with more than 17,000 solar cells. An attempt to fly around the world in stages using only solar energy will be made in 2015. (Photo by Ruben Sprich/Reuters)

Dutch artist Daan Roosegaarde paid homage to Vincent Van Gogh's famous “Starry Night” painting by creating a glowing bike path relying on solar-powered LED lights. The 650-yard route which opened November 12, 2014 extends between Eindhoven and Neunen, Netherlands, where Van Gogh spent part of his life. Its the first event marking the 125th anniversary of Van Gogh's death July 29, 2015. (Photo by Pim Hendriksen/Studio Roosegaarde)

As the world marks the International Day of the Girl Child, women's rights activists point to progress on a wide array of issues but say more needs to be done to protect girls from child marriage, sexual assault and other forms of exploitation. Here is a selection of pictures showing the daily lives of girls across the globe, all taken by female Associated Press photojournalists. Here: In this December 14, 2015, file photo, a young clown rides in the back of a car following a procession to the Basilica of Our Lady of Guadalupe in Mexico City. Hundreds belonging to various clown associations made their annual pilgrimage to the Basilica to pay their respects to the Virgin of Guadalupe, Mexico's patron saint. (Photo by Rebecca Blackwell/AP Photo)

A bomb-laden Su-25 jet at the Hmeimim air base in December 2015. Russia's lease agreement obliged Assad’s military to safeguard the perimeter of the Hmeimim base, while giving Moscow legal jurisdiction over the facilities inside. Negotiating perimeter protection from Syria’s new rulers will be vital for the Russian bases in an era of wire-controlled drones immune to jamming. (Photo by AP Photo)

Dismaland is a temporary art project organized by street artist Banksy, constructed in the seaside resort town of Weston-super-Mare in Somerset, England.The secretive pop-up exhibition at the Tropicana, a disused lido, is "a sinister twist on Disneyland" that opened during the weekend of 21 August 2015. Banksy has described it as a "family theme park unsuitable for children".

Members of the Oath Keepers and general public return fire during a simulated attack as they take part in a tactical training session in northern Idaho, U.S. October 1, 2016. In April 2015 Reuters photographer Jim Urquhart was assigned to cover the Oath Keepers during a tour of the Sugar Pine gold mine in Oregon after the group of former cops, military, firefighters and other first responders had risen to prominence during a standoff in Nevada over land rights. (Photo by Jim Urquhart/Reuters)

A girl floats in a bucket in the village of Ologa in the western state of Zulia October 23, 2014. This year the Catatumbo Lightning was approved for inclusion in the 2015 edition of Guinness World Records, dethroning the Congolese town of Kifuka as the place with the world's most lightning bolts per square kilometer each year at 250. Scientists think the Catatumbo, named for a river that runs into the lake, is normal lightning that just happens to occur far more than anywhere else, due to local topography and wind patterns. (Photo by Jorge Silva/Reuters)

With their wings at full length, these beautiful golden eagles soar through the skies in a glorious training session to hunt their prey. Others sit on the arms of their owners and trainers. Batzaya Choijiljav, 41, from Mongolia has taken these magnificent pictures at the annual traditional Kazakhs festival, October 2015. (Photo by Batzaya Choijiljav/Caters News)