People on motor bikes celebrate American President Barack Obama's visit to Kenya by holding up a photo, center top, of the president and First Lady Michelle Obama in Kisumu, Kenya, Saturday, July 25, 2015. President Barack Obama heralded Africa as a continent “on the move” Saturday as he opened a U.S.-sponsored business summit in Kenya, the East African nation where he has deep family ties. (Photo by AP Photo)

This undated image provided by World View shows World View capsule and balloon spacecraft that will rise to 100,000 feet above Earth for passengers to see the curvature of the planet and the blackness of space. Space tourism companies are employing designs including winged vehicles, vertical rockets with capsules and high-altitude balloons. While developers envision ultimately taking people to orbiting habitats, the moon or beyond, the immediate future involves short flights into or near the lowest reaches of space without going into orbit. (Photo by World View via AP Photo)

Police officers try to stop medical students as they protest against Sri Lanka's crippling economic crisis, outside the Health Ministry in Colombo on April 6, 2022. (Photo by Ishara S. Kodikara/AFP Photo)

Young demonstrators (many shirtless) shout and cheer as they overturn a truck trailer in the Reflecting Pool on the Mall facing the Washington Monument during the “Honor America Day Smoke-In” thrown by marijuana activists to protest the official “Honor America Day” ceremonies being held at the Lincoln Memorial, Washington, DC, July 4, 1970. (Photo by David Fenton/Getty Images)

Men try to get control of a bucking horse a Tradition Day rodeo exhibition during, in San Antonio de Areco, Argentina, Sunday, November 13, 2022. Tradition Day, aimed to preserve gaucho traditions, is celebrated to honor the birth of Argentine writer Jose Hernandez, author of the country's national poem, “The Gaucho Martin Fierro”. (Photo by Natacha Pisarenko/AP Photo)

Russian people walk during heavy rain in Moscow, Russia on 17 September 2020. Over two hours a third of the monthly average rainfall fell in Moscow. (Photo by Yuri Kochetkov/EPA/EFE)

Bystanders look at MV Wakashio bulk carrier that had run aground and from which oil is leaking near Blue Bay Marine Park in south-east Mauritius on August 6, 2020. The carrier, belonging to a Japanese company but Panamanian-flagged, ran aground on July 25 and its crew was evacuated safely. The ship was empty at the time but was carrying 200 tonnes of diesel and 3,800 tonnes of bunker fuel, according to the local press. (Photo by Dev Ramkhelawon/L'Express Maurice/AFP Photo)

Police officers wield their batons against activists from various student unions during a protest march demanding jobs and better education facilities, in Kolkata, India, February 11, 2021. (Photo by Rupak De Chowdhuri/Reuters)