Migrant children run away from clashes with Mexican National Guards after their group crossed the Suchiate River on foot from Guatemala to Mexico, on the riverbank near Ciudad Hidalgo, Mexico, Monday, January 20, 2020. More than a thousand Central American migrants hoping to reach the United States marooned in Guatemala are walking en masse across a river leading to Mexico in an attempt to convince authorities there to allow them passage through the country. (Photo by Santiago Billy/AP Photo)

A boy takes a picture of a car crash in Shenzhen, Guangdong province, August 4, 2014. Two passengers were sent to hospital but no death was reported as a result of the accident, according to local media. (Photo by Reuters/Stringer)

A pro-Russian armed man secures crash site wreckage of the Malaysia Airlines Boeing 777 plane (flight MH17) at the site of the plane crash near the settlement of Grabovo in the Donetsk region November 16, 2014. Local emergency services have begun collecting parts of the wreckage from its crash site in the middle of the conflict zone, Dutch air accident investigators said on Sunday. Dutch inspectors had hoped to collect the parts themselves, following the downing of the flight on July 17 that killed 298 people, two thirds of them Dutch citizens. But they remain concerned about the safety of their staff in the rebel-held conflict zone, and so have decided to work with local services following an initial focus on finding human remains and belongings. (Photo by Antonio Bronic/Reuters)

Cave Diver, Anhumas Abyss, Bonito, Brazil: The Anhumas Abyss is an underground cavern with a crystal-clear lake below, more than 260 feet (79 m) deep. A visitor must enter through a narrow opening at the top of the chamber and rappel into the cave. Snorkeling and scuba diving in the lake reveal amazing scenery. Distinctive, conical limestone stalagmites and stalactites occupy the lake and the surrounding area, some reaching 65 feet (20 m) high. (Photo by Marcio Cabral/Nature’s Best Photography Awards 2017)

Merit Prize Winner: “A Well Earned Rest in the Sahara”. This photo of Moussa Macher, our Tuareg guide, was taken at the summit of Tin-Merzouga, the largest dune (or erg) in the Tadrat region of the Sahara desert in southern Algeria. Moussa rested while waiting for us to finish our 45-minute struggle to the top. It only took ten minutes of rolling, running, and jumping to get back down. The Tadrat is part of the Tassili N'Ajjer National Park World Heritage area, famous for its red sand and engravings and rock paintings of cattle, elephants, giraffes, and rhinos that lived there when the climate was milder. Photo location: Summit of Tin-Merzouga, Tadrat, Tassili N'Ajjer National Park, Algeria. (Photo and caption by Evan Cole/National Geographic Photo Contest)

Lava erupts from the Piton de la Fournaise “Peak of the Furnace” volcano, on the southeastern corner of the Indian Ocean island of Reunion Saturday, August 1, 2015. Spewing red-hot lava, one of the most active volcanoes in the world is currently erupting on this Indian Ocean island, where the world's attention has been focused since a wing fragment believed to be from the missing Malaysian jet was discovered washed up on a beach. The lava fountains are shooting as high as 40 meters (44 yards) and are creating cones that are about 20 meters high after only one day of eruption, said Peltier. The volcano is in the Reunion National Park – a world heritage site. The volcano is not seen as dangerous because the lava flows down the east side of the mountain through an uninhabited area called the Grand Brule, or the Big Burned, toward the sea. The last times the volcano threatened the population was in 1977 and 1986. (Photo by Ben Curtis/AP Photo)

A pigeon, known as Siyah Kinifirli, with an approximate market value of 1000 Turkish Lira ($263), bred by 23-year-old Ismail Ozbek, is pictured in Sanliurfa, Turkey, December 23, 2016. As night-time approaches in Sanliurfa, southeastern Turkey, most of the alleyways of the city's old bazaar are emptying out of buyers and vendors, except for one. (Photo by Umit Bektas/Reuters)

English actress Diana Rigg as “Emma Peel” is tied to a railway track as a miniature train advances on her in a scene from the television series “The Avengers” in 1968. Rigg died at her home in London on 10 September 2020, at the age of 82. (Photo by Popperfoto via Getty Images/Getty Images)