The Hubble Space Telescope is shown following its release from the space shuttle Discovery Wednesday, February 19, 1997. The Hubble Space Telescope, one of NASA'S crowning glories, marks its 25th anniversary on Friday, April 24, 2015. With more than 1 million observations, including those of the farthest and oldest galaxies ever beholden by humanity, no man-made satellite has touched as many minds or hearts as Hubble. (Photo by AP Photo/NASA)

Descendants of American Southerners Wearing Confederate-era dresses and uniforms dance during a party to celebrate the 150th anniversary of the end of the American Civil War in Santa Barbara d'Oeste, Brazil, Sunday, April 26, 2015. For many of the residents of Santa Barbara d'Oeste and neighboring Americana, in Brazil's southeastern Sao Paulo state, having Confederate ancestry is a point of pride and is celebrated in high style at the annual “Festa dos Confederados”, or “Confederates Party” in Portuguese. (Photo by Andre Penner/AP Photo)

An employee of the National Park Service takes a selfie with President Barack Obama, left, in the background meeting with the crowd after a tour of Everglades National Park on Earth Day, Wednesday, April 22, 2015, in Florida. Obama used the visit to warn of the damage that climate change is already inflicting on the nation's environmental treasures. (Photo by Lynne Sladky/AP Photo)

A stuffed rabbit doll sits among children's beds standing in the abandoned kindergarten of Kopachi village located inside the Chernobyl Exclusion Zone on September 29, 2015 near Chornobyl, Ukraine. Kopachi, a village that before 1986 had a population of 1,114, lies only a few kilometers south of the former Chernobyl nuclear power plant, where in 1986 workers inadvertantly caused reactor number four to explode, creating the worst nuclear accident in history. (Photo by Sean Gallup/Getty Images)

In this November 3, 2015 file photo, Afghan Taliban fighters listen to Mullah Mohammed Rasool, the newly-elected leader of a breakaway faction of the Taliban, in Farah province, Afghanistan. Despite US President Donald Trump’s pronouncement that there would be no talks with the Taliban following a series of deadly attacks in Kabul, officials say talks continue, but neither side trusts the other and neither believes the other negotiates independently. (Photo by AP Photo/Stringer)

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)

In this March, 2015 photo, a person sits at an upright piano that had been hauled up to Topanga Lookout in the Santa Monica Mountains in Calabasas, Calif. For a couple of days last week, a Southern California hilltop was alive with the sound of mystery. Hikers venturing to Topanga Lookout found a battered upright piano sitting on a graffiti-scrawled concrete slab with a panoramic view over the mountains between Calabasas and the Pacific Ocean. Turns out, the piano was used for a music video by Seattle-based artist Rachel Wong. The cinematographer, Michael Flotron, says he and four others used a dolly and rope to haul the 350-pound instrument a mile up the trail on Tuesday. After the shoot, it was too dark to get the piano back down. Flotron says people seem happy to leave it there. But if necessary, he'll haul the piano back down. (Photo by Michael Flotron/AP Photo)