Mount Sinabung is seen during an eruption from Surbakti village in Karo, North Sumatra, Indonesia, April 20, 2015. The local government is preparing the relocation of residents from three of the villages that were destroyed. (Photo by Tibta Pangin/Getty Images/Anadolu Agency)

A prototype battery-powered plane, called Greased Lightning or GL-10 is pictured flying at NASA's Langley Research Center in this undated handout photo obtained by Reuters May 1, 2015. The plane, which has 10 engines and can take off like a helicopter and fly efficiently like an aircraft, is currently in the design and testing phase. (Photo by Reuters/NASA)

People walk past debris on May 3, 2015 in Bhaktapur, Nepal. A major 7.8 earthquake hit Kathmandu mid-day on Saturday, and was followed by multiple aftershocks that triggered avalanches on Mt. Everest that buried mountain climbers in their base camps. (Photo by David Ramos/Getty Images)

The figure of an eight-year-old boy is seen inside a suitcase on a Spanish civil guard scanner screen at the border between Morocco and Spain's north african enclave Ceuta, Spain in this handout photo released May 8, 2015. A 19-year-old woman was arrested May 7, 2015 for the attempted smuggling of the boy, who was checked by medics and handed over to juvenile prosecutors office, according to authorities. (Photo by Reuters/Ministerio Del Interior)

Elaine Vandiver shares a moment with a two-year old alpaca as they touch noses as she washes him at her farm at 1560 Stateline Road Monday, May 11, 2015, in Walla Walla, Wash. (Photo by Michael Lopez/Walla Walla Union-Bulletin via AP Photo)

A model wears a floral head dress as she promotes a chain of garden centres at the Royal Horticultural Soceity's Chelsea Flower Show in London, Britain, May 18, 2015. (Photo by Toby Melville/Reuters)

A jockey falls from his buffalos during Barapan Kebo or buffalo races as part of the Moyo festival on September 30, 2014 in Sumbawa Island, West Nusa Tenggara, Indonesia. The traditional Buffalo races, known as Barapan Kebo, are held by Samawa tribes in muddy rice fields to celebrate and provide entertainment ahead of the annual planting season. Jockeys secure themselves on a wooden structure attached to the buffalo, and maneuver across the mud in a race to the finish line. The jockeys weild long sticks, in a similar style to jousting, and direct them towards targets called “Saka”. (Photo by Ulet Ifansasti/Getty Images)

A woman walks through flood water during heavy downpour at a street in Genoa, Italy, 10 October 2014. At least one person died due to flooding after heavy rains caused the Bisagno river, which runs through Genoa city to overflow. Part of the city was in black-out with flooded streets and parked cars dragged away by the water's force. (Photo by Luca Zennaro/EPA)