Pulitzer Prize-winning journalist and National Geographic Explorer Paul Salopek has been walking across the world, retracing human migration and documenting the stories of the people he meets along the way. Setting out from Ethiopia in 2013, Salopek has traversed the Middle East, Central Asia, the Indian subcontinent, and East Asia on foot—and now he has arrived in North America, where he will walk toward his final destination: the southern tip of South America. Look back at his incredible journey and the people he's met on the Out of Eden Walk so far.

What did it take to capture the first underwater color photographs in the 20th century? Powerful explosives and a lot of patience. Scientist W. H. Longley and National Geographic photographer Charles Martin hacked autochrome plates to be more sensitive to light and used magnesium powder to create a flash underwater—a process that burned Longley’s hands and temporarily incapacitated him after a test run. But the results were stunning and transformed how we saw the ocean floor and the creatures who lived there. 

Thanks for reading today’s newsletter, which was edited and curated by Sidney Madden with the help of National Geographic’s photo team. It was produced by Alisher Egamov. Did someone forward this to you? Sign up here to catch next week’s Photo of the Week newsletter.