Competitors in the Big Air challenge at the Proryv-2016 festival of extreme sports in Moscow, Russia on March 27, 2016. (Photo by Xinhua/Rex Features/Shutterstock)

Athletes from Australia's Olympic team going to the 2016 Olympics in Rio present their uniforms alongside Brazilian Samba dancer Sashya Jay at an official unveiling ceremony at Sydney's Bondi Beach, March 30, 2016. (Photo by Jason Reed/Reuters)

Myanmar revellers take part in celebrations on the fifth and last day marking Thingyan, a water festival which brings in the country's new year, in Yangon on April 16, 2016. The Buddhist festival of water pouring symbolizes spiritual cleansing and begin the new year free from worldly impurities with celebrants devoting the four days of Thingyan in merry making of water dousing until the eve of new year. (Photo by Romeo Gacad/AFP Photo)

Michael Grant, 28, “Philly Jesus”, carries a 12 foot cross 8 miles through this blighted area of North Philadelphia towards LOVE Park in Center City as part of a Christmas walk to spread the true message of the holiday in Philadelphia, Pennsylvania December 20, 2014. As many as a half dozen others joined him for numerous miles as he trekked southward down Broad Street. Some shouted “Praise Jesus!” and “Thank you for doing this!” at the sight. Nearly everyday for the last 8 months, Grant has dressed as Jesus Christ, and walked the streets of Philadelphia to share the Christian gospel by example. He quickly acquired the nickname of “Philly Jesus”, which he has gone by ever since. (Photo by Mark Makela/Reuters)

Some are in it just for the money, others to help buy a meal. Then there are those who trade for fun or to spend time among friends. Millions of investors – pensioners, security guards, high-school students – dominate China's stock markets, conducting about 80 percent of all trades. Retirees gather in brokerage houses dotted around China also to enjoy some company and savour the air conditioning on hot days. Some start as young as 13, trading from home with an eye on future careers in finance. Winning isn't guaranteed. This year, among the most turbulent in China's financial history, its stock markets more than doubled in the six months to May, only to crash amid concerns that growth in the country, which makes everything from cars to steel, is slowing faster than previously thought. (Photo by Aly Song/Reuters)

Wedges of an orange generate enough current and electrical juice – 3.5 volts – to power an LED. The fruit’s citric acid helps electrons flow from galvanized nails to copper wire in this 14-hour exposure. This image was published in September’s Visions of Earth, a trio of photos that appear in each issue of National Geographic. (Photo by Caleb Charland/National Geographic)

This incredible panoramic photographs are distorted to create miniature worlds and terrifying tunnels. (Photo by Caters News)

“Strike Through The Mothership”. Every May for the last 3 years I have driven down to Tornado Alley to capture some amazing storms. This supercell held so much promise to drop a tornado but one small shift in the atmosphere and all that it produced was an extreme lightning show. Photo location: Broken Bow, Nebraska. (Photo and caption by Vanessa Neufeld/National Geographic Photo Contest)