Vivian Odhiambo, 24, frys samosas in the trading centre of Kogelo, west of Kenya's capital Nairobi, July 14, 2015. Odhiambo said, “Obama is our hero and we wait to welcome him back home again. We in Kogelo have witnessed general growth and we are proud of being associated with the Obamas”, she added. As U.S. President Barack Obama visits Kenya, a personal connection to his father's birthplace of Kogelo dominates a trip that Kenyans view as a native son returning home. Residents from a herdsman to a housewife share their views on what Obama has achieved and what they would like to see next. (Photo by Thomas Mukoya/Reuters)

Children eat watermelons to meet the “beginning of autumn” at a kindergarten in Handan, China on August 7, 2015. Chinese tradition to eat watermelons or peaches before that day symbolises “biting away summer”. The solar term ‘beginning of autumn’ falls on 8 August this year. (Photo by Xinhua/REX Shutterstock)

A keeper feeds a four-week-old jaguar while presenting it to the media, at a zoo in Ciudad Juarez, Mexico, October 14, 2015. (Photo by Jose Luis Gonzalez/Reuters)

Black-headed gulls sit on pickets at a riverside in Tokyo, Japan, December 27, 2015. (Photo by Toru Hanai/Reuters)

A wide-angle view shows the ascent of the shuttle Challenger on January 28, 1986. In the seconds after ignition, the rocket engines' hot blast began the process of destruction. (Photo by NASA)

Female of pygmy hippopotamus called Malaya from Netherlands in zoo in Dvur Kralove nad Labem, Czech Republic, February 22, 2016. (Photo by David Tanecek/CTK via ZUMA Press)

A woman, wearing a traditional Sevillana dress, performs as she asks for alms in downtown Malaga, Spain, April 28, 2016. (Photo by Jon Nazca/Reuters)