A lightning strikes St Peter's dome at the Vatican on February 11, 2013. Pope Benedict XVI announced today he will resign as leader of the world's 1.1 billion Catholics on February 28 because his age prevented him from carrying out his duties – an unprecedented move in the modern history of the Catholic Church. (Photo by Filippo Monteforte/AFP Photo)

Valery Bystritskii, 10, gets a fellow student into a lock at Bunny's Gym in July 2015 in Winchester, Tennessee. (Photo by Mike Saliba/Barcroft USA)

An Economic Freedom Fighters supporter shows a mock weapons during a demonstration in Pretoria on April 12, 2017 calling for South African President Jacob Zuma to resign. Tens of thousand demonstrators took part in the march to Union Buildings, the official seat of government, which was organised on Zuma's 75th birthday and came after nationwide rallies against the president last week. Zuma's recent sacking of respected finance minister Pravin Gordhan has fanned years of public anger over government corruption scandals, record unemployment and slowing economic growth. (Photo by Marco Longari/AFP Photo)

In this handout provided by the National Aeronautics and Space Administration (NASA), SpaceX's Falcon 9 is moved to the launch pad prior to the rocket's Thales Alenia Space launch attempt on April 26, 2015 in Cape Canaveral, Florida. (Photo by NASA via Getty Images)

Musicians of the alphorn band "Holdersberger Alp- Traum- Blaeser" perform their skills on a raft floating on the Elbsee lake near Aitrang, southern Germany, on June 11, 2017. (Photo by Karl-Josef Hildenbrand/AFP Photo/DPA)

Hindu women perform a ritual known as Aarti around a Shivling (a symbol of Lord Shiva) on the last day of Jaya Parvati Vrat festival in Ahmedabad, India, July 10, 2017. (Photo by Amit Dave/Reuters)

A Libyan fireman stands in front of smoke and flames rising from an oil storage tank at an oil facility in northern Libya's Ras Lanouf region on January 23, 2016, after it was set ablaze earlier in the week following attacks launched by Islamic State (IS) group jihadists to seize key port terminals. (Photo by AFP Photo/Stringer)

A 6-month old female giant panda cub, an offspring of Xing Xing, formerly known as Fu Wa and Liang Liang, formerly known as Feng Yi, plays at the Giant Panda Conservation Center at the National Zoo in Kuala Lumpur, Malaysia, Thursday, February 18, 2016. (Photo by Joshua Paul/AP Photo)