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)

Tourists look at other festival-goers playing in the mud during the Boryeong Mud Festival at Daecheon beach in Boryeong, about 190 km (118 miles) southwest of Seoul, July 19, 2013. About 2 to 3 million domestic and international tourists visit the beach during the annual mud festival, according to the festival organisers. (Photo by Lee Jae-Won/Reuters)

The antennas of the European Southern Observatory's Atacama Large Millimeter/Submillimeter Array, also known as ALMA, are set against the splendor of the Milky Way in this picture by Babak Tafreshi. Construction of the full ALMA array is due to be completed in Chile's Atacama Desert in 2013, but the facility is already making scientific observations with a partial array of antennas. (Photo by ESO/B. Tafreshi/TWAN)

Old Heidelberg, Dog with Pipe, 1905. (Photo by Detroit Publishing Company)

A doll forms part of a sculpture as part of an exhibit titled The Sea Isn't Made for Fish at Rio de Janeiro Federal University in Rio de Janeiro, Brazil, Monday, June 1, 2015. Art students have taken advantage of a material they have in endless supply trash to create an exhibition that aims to draw attention to the fetid state of the citys Guanabara Bay, where the Olympic sailing events are to be held next year. (AP Photo/Silvia Izquierdo)

Women kiss each other as people celebrate outside the Stonewall Inn in the Greenwich Village neighborhood of New York June 26, 2015. The Supreme Court ruled on Friday that the U.S. Constitution provides same-s*x couples the right to marry, handing a historic triumph to the American gay rights movement. (Photo by Eduardo Munoz/Reuters)

Francisco Solano poses for a photo in his bird-feather suit after attending a Mass commemorating the feast day of St. Francis Solano, in Emboscada, Paraguay, Friday, July 24, 2015. Some 500 people attended the festivity – a mix of indigenous and Guarani Indian beliefs. The festival begins with a Mass, continues with a procession of the diminutive wooden statue of St. Francis, and ends with people dancing in suits made with black, white, brown and grey feathers. (Photo by Jorge Saenz/AP Photo)

A motorcycle carrying protesters holding a placard using the acronym of the national electoral commission, drives ahead of demonstrators on foot calling for the disbandment of the commission over allegations of bias and corruption, in downtown Nairobi, Kenya Monday, June 6, 2016. (Photo by Ben Curtis/AP Photo)