Boys walk home for lunch from school in the village of Kogelo, west of Kenya's capital Nairobi, July 16, 2015. U.S. President Barack Obama visits Kenya and Ethiopia later this month. His ancestral home of Kogelo is home to Sarah Hussein Obama, his step-grandmother. The Kenyan village, burial place of Obama's father, features an open-pit goldmine, a pork butcher's, a school named after their most famous son and outdoor market stalls. Villagers get around by motorbike taxi or on foot while a donkey-cart transports water. Children, some of them named Obama in honour of the President, walk to and from school together. (Photo by Thomas Mukoya/Reuters)

Jassen Todorov, 40, from San Francisco is a professor of music at San Francisco State University, but he took to helicoptering in his spare time. While he was content to keep the panoramic views he witnessed to himself, Todorov has now paired his passion for flying with photography to capture some of the United States’ undiscovered vistas. Here: Grand Prismatic Spring, Yellowstone, Wyoming. (Photo by Jassen Todorov/Caters News)

Rhodochrosite is a manganese carbonate mineral with chemical composition MnCO3. In its (rare) pure form, it is typically a rose-red color, but impure specimens can be shades of pink to pale brown. It streaks white, and its Mohs hardness varies between 3.5 and 4. Its specific gravity is between 3.5 and 3.7. It crystallizes in the trigonal system, and cleaves with rhombohedral carbonate cleavage in three directions.

A runner takes part in the International World's coldest marathon at minus 53 degrees (–63.4 Fahrenheit) near Oymyakon, the republic of Sakha, also known as Yakutia, Russian Far East, Saturday, January 22, 2022. Sixty five runners, including athletes from the United Arab Emirates, United States and Belarus, started the run at extremely low temperature in Oymyakon, Yakutia's Pole of Cold. The international team of men and women ran full distance and half-marathon. (Photo by Ivan Nikiforov/AP Photo)

A fan looks at the Germany flag before the 2014 World Cup final between Germany and Argentina at the Maracana stadium in Rio de Janeiro July 13, 2014. (Photo by Darren Staples/Reuters)

The brutalist war memorials found throughout the former Yugoslavia were weird enough when they were built in the 1960s and 70s. Today, separated by the end of an architectural movement and the disintegration of the country, they seem almost alien. Belgian photographer Jan Kempenaers treats them purely as artistic objects in his book, “Spomenik”, named for the Serb-Croat word for monument. Known for photographing geographical oddities, Kempenaers was captivated by the spomenik after seeing them in an art encyclopedia. After hearing that many had been destroyed or abandoned, he set out to record what was left. (Photo by Jan Kempenaers)

Battle-weary American troops withdraw from Yong San in Korea. (Photo by Keystone/Getty Images). 1950

Gina Labianca (L) tries on a super woman outfit as Charlie Lucas tries a snow white Costume at the Halloween MegaStore Miami Beach on October 21, 2011 in Miami Beach, Florida. The megastore is a temporary location for the store which opened for the holiday to sell costumes, masks and other items to people needing to dress up for the evening of October 31 when costumed people around the world observe the day. (Photo by Joe Raedle/Getty Images)