A handout picture provided by Solar Impulse on 18 March 2015 shows the Swiss solar-powered plane Solar Impulse 2, HB-SIB, taking off with Swiss explorer Andre Borshberg on board for the third leg Ahmedabad to Varanasi, of the Round-The-World, in Ahmedabad, India, 18 March 2015. Swiss explorers Bertrand Piccard and Andre Borschberg attempt to circumnavigate the world flying with an aircraft, with a 72 metres wingspan, powered only by solar energy without a drop of fuel. (Photo by EPA/Solar Impulse)

A military police officer patrols in the Roquette Pinto shantytown, part of the Mare slum complex in Rio de Janeiro, Brazil, Wednesday, April 1, 2015. The Brazilian army has begun to pull out of one of Rio de Janeiro's most violent slums, with police assuming responsibility for security in the area. (Photo by Felipe Dana/AP Photo)

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)

Russian Mi-28N from the Berkuty (Golden Eagles) helicopter display team fly in formation during the “Aviadarts” military aviation competition at the Dubrovichi range near Ryazan, Russia, August 2, 2015. The aircraft started dipping down due to back propeller failure and crashed, killing one of two pilots, according to a Reuters photographer and official representatives of the competition. The aviation contest is part of the International Army Games, which are held in Russia from the 1st till the 15th of August with participants from 17 countries, according to organizers. (Photo by Maxim Shemetov/Reuters)

Ultra- trailers compete at sunrise on September 2, 2017 in Courmayeur, Italy, during the 15 th edition of the Mount Blanc Ultra Trail (UTMB), a 170 km race around the Mont Blanc crossing France, Italy and Switzerland. The 15 th Ultra- Trail du Mont- Blanc (UTMB) is a mountain ultramarathon with numerous passages in high altitude (>2500 m) and in difficult weather conditions (night, wind, cold, rain or snow). (Photo by Jeff Pachoud/AFP Photo)

The work entitled “Trip 1, Trip II, Trip III” by April Pine is pictured before dawn at Sculpture By The Sea at Bondi Beach on October 19, 2017 in Sydney, Australia. This year the outdoor exhibition celebrates its 21st birthday with 104 exhibiting artists from Australia and around the world and runs from the 19th October-5th November 2017. (Photo by Brook Mitchell/Getty Images)

Tourists photograph a red dear stag visiting a car park near Glen Coe on December 1, 2017 in Glen Coe,Scotland. On the first day of the meteorological calendar, the UK was experiencing slightly warmer temperatures today with weather forecasters indicating that the recent cold spell is almost over. Yesterday's snow across eastern parts of England is expected to melt away over the course Friday as temperatures start to rise. (Photo by Jeff J. Mitchell/Getty Images)

A man wear a phallic-shaped hat during Kanamara Matsuri (Festival of the Steel Phallus) on April 1, 2018 in Kawasaki, Japan. The Kanamara Festival is held annually on the first Sunday of April. The pen*s is the central theme of the festival, focused at the local pen*s-venerating shrine which was once frequented by prostitutes who came to pray for business prosperity and protection against sexually transmitted diseases. Today the festival has become a popular tourist attraction and is used to raise money for HIV awareness and research. (Photo by Carl Court/Getty Images)