A reveller from Uniao da Ilha samba school performs during the second night of the carnival parade at the Sambadrome in Rio de Janeiro, Brazil February 27, 2017. (Photo by Pilar Olivares/Reuters)

Free Syrian Army fighters stand near an ambulance on the eastern edge of the northern Syrian town of al-Bab, Syria, February 27, 2017. (Photo by Khalil Ashawi/Reuters)

The possible surface of TRAPPIST-1f, one of seven newly discovered planets in the TRAPPIST-1 system that scientists using the Spitzer Space Telescope and ground based telescopes have discovered. (Photo by Reuters/NASA/JPL-Caltech)

Cockpit of a SCG 0003S racecar is seen during the 87th International Motor Show at Palexpo in Geneva, Switzerland March 8, 2017. (Photo by Arnd Wiegmann/Reuters)

A resident looks at a wildfire in Vina del Mar, Chile, March 12, 2017. Forest fires are a regular feature of Chile's hot, arid summers, but a nearly decade-long drought combined with historically high temperatures have created tinder-like conditions in the nation's central regions. (Photo by Rodrigo Garrido/Reuters)

A man presents a self-made robot that local media reported is able to carry a person, in Heihe, Heilongjiang province, China, April 5, 2017. (Photo by Reuters/China Daily)

Girls dressed in traditional costumes run as men throw water on them as part of Easter celebrations during a presentation to the media in Mezokovesd, Hungary, April 13, 2017. (Photo by Laszlo Balogh/Reuters)

Soldiers pose for a photo during the flower exhibition marking the 105th birth anniversary of the country's founding father, Kim Il Sung in Pyongyang, North Korea April 16, 2017. (Photo by Damir Sagolj/Reuters)