Among the fish populations that could be harmed by the Xayaburi dam in Laos is the critically endangered Mekong giant catfish, considered by the Guinness Book of World Records to be the world’s largest freshwater fish. The fish, which grows to 650 pounds and about 10 feet long, is only found in the Mekong River. It is migratory, moving between downstream habitats in Cambodia upstream to northern Thailand and Laos each year to spawn. Some experts fear the Xayaburi dam could block the migration and drive the giant catfish to extinction. (Photo by Courtesy of Zeb Hogan/University of Nevada, Reno)

Alex Plunkett, left, and Sean Hart, both of Arlington, Va., join hundreds participating in the annual International Pillow Fight Day on April 5. Massive pillow fights broke out on the Mall in Washington and in cities around the world. (Photo by Marvin Joseph/The Washington Post)

It is said that Torajans are people who “live to die”. For this Indonesian ethnic group, funerals are such extravagant events that they sometimes attract tourists. Families can postpone burials years (and the deceased are considered sick and hosted at home until the funeral) until the family can raise enough money and gather as many relatives as possible. And then it’s a jubilant multiday social event with a parade, dances and animal sacrifices. Agung Parameswara photographed these funerary practices when he traveled to South Sulawesi province, where the Torajans live. (Photo by Agung Parameswara/The Washington Post)

A layer of morning mist still covers the fields as the sun rises into the morning sky over Hohenfelden, Thuringia state, Germany, early 07 September 2016. Meteorologists predict the weather to become warm and sunny in the region with temperatures reaching around 256 degrees Celsius. (Photo by Martin Schutt/EPA)

A 6-week old Fennec fox, the smallest species of foxes, and a native to the Sahara desert in Africa, looks as its mother eats in the Ramat Gan Safari Park near Tel Aviv, Israel, Sunday, November 6, 2016. Sagit Horowitz, the safari spokeswoman said four Fennec foxes were born about six weeks ago. (Photo by Ariel Schalit/AP Photo)

A cat walks past a Soyuz space ship installed at a museum, at the Russian leased Baikonur cosmodrome, Kazakhstan, Tuesday, November 15, 2016. The start of the new Soyuz mission to the International Space Station (ISS) is scheduled on early Friday, Nov. 18 local time. The Russian rocket will carry French astronaut Thomas Pesquet, Russian cosmonaut Oleg Novitsky and U.S. astronaut Peggy Annette Whitson. (Photo by Dmitri Lovetsky/AP Photo)

Though schools around the globe have different start dates, calendars and traditions, the first day of a new term is an exciting time filled with the prospects of gaining more knowledge, making new friends and building community. Here: Schoolchildren attend their first lesson on Knowledge Day in the town of Turov, Zhytkavichy District, Gomel Region, Belarus on September 1, 2017. Knowledge Day marks the beginning of a new school year in Belarus and is celebrated on September 1. (Photo by Viktor Drachev/TASS via Getty Images)

Eddie Ladd and Gwyn Emberton perform as Dylan and Caitlin Thomas in “Caitlin” at the Lauriston Hall, Edinburgh, Scotland on August 25 2017. (Photo by Mary Turner/Reuters)