NAIROBI, Kenya -- On the eve of an unimaginably long walk -- one that starts in Africa, winds through the Middle East, across Asia, hops over to Alaska, goes down the western United States, then Central and South America and ends in Chile -- one question nagged journalist Paul Salopek: Should he take his house keys?
Salopek on Thursday departed a small Ethiopian village and took the first steps of a planned 21,000-mile (34,000-kilometer) walk that will cross some 30 borders, where he will encounter dozens of languages and scores of ethnic groups. The 50-year-old's quest is to retrace man's first migration from Africa across the world in a go-slow journey that will force him to immerse himself in a variety of cultures so he can tell a global mosaic of people stories.
The Ethiopia-to-Chile walk -- which took human ancestors some 50,000 years to make -- is called Out of Eden and is sponsored by National Geographic, the Knight Foundation and the Pulitzer Center for Crisis Reporting. A two-time Pulitzer Prize winner, the American plans to write one major article a year with periodic updates every 100 miles or so.
"Often the places that we fly over or drive through, they aren't just untold stories, but they are also the connective tissues between the stories of the day," Salopek told The Associated Press by satellite phone from the village of Herto Bouri, his starting point, late Wednesday.
Those flyover places explain how environment or education are connected to the economy -- stories that are more nuanced and complicated "that take slowing down to explain," he said.
Though Salopek's planned walk may be among the longest in modern times -- Guinness World Records doesn't track "longest walk" because such a feat can't be standardized -- such long, investigative walks have been done before.
Rory Stewart, now a British parliamentarian, walked across Iran, Pakistan, Nepal, and then circled back to post-Taliban Afghanistan to walk from Herat to Kabul, a journey chronicled in the 2005 book "The Places In Between." Stewart's walk took 21 months.
"The best thing about it for me was simply that it gave me access to people and communities. It forced you to stop every 20 or 25 miles. It forced you to spend nights in village homes," said Stewart, who spends six weeks every year walking through his political district. "For me the real great thing about this kind of journey is that we live in a world which is very focused on destinations, a city or a tourist site, which ignores 99 percent of the country."
Stewart's advice to Salopek is that he find people to be with at night. Long days of endless walking leave you tired, hungry and wanting solitude, but Stewart said the best hours of Salopek's journey will not be during daylight, but in the evening hours around a dinner table or fireplace.
That's what Salopek plans to do. He hopes to walk with local people throughout his journey, learning new languages or finding English speakers along the way. He says the journey will slow down his own process of writing, and he hopes he can also slow down readers who live in a world flooded with information.
"I love long form writing, and I'm hoping that there will be an audience for this, and that people will be willing to wait for stories to come episodically," said Salopek, who won the 1998 Pulitzer Prize for explanatory reporting and the 2001 Pulitzer for international reporting, from Africa, both while he wrote for the Chicago Tribune.
On a personal level, Salopek wanted to see if the trip will help him slow down and enrich his own work.
Salopek says his family has been "tremendously supportive" of his long journey. His wife may join him for parts of the walk. "While this is a major, major undertaking, by my standards it's not entirely out of character," he said.
Riall Nolan, a professor of anthropology at Purdue University who has lived and worked in Senegal, Tunisia, Sri Lanka and Papua New Guinea, called Salopek's trip extraordinary and "incredibly ambitious." He said he hopes Salopek has the physical and mental stamina to finish.
"What is he going to get out of this? He's going to learn a lot about human diversity. He can tell his grandchildren and say to people with authority: `I have seen many of the thousands of ways people can be human.' We are an amazingly diverse species. There is not just one way to be human," Nolan said.
Stewart said he was tempted to carry a weapon on his long journey in Nepal or Afghanistan -- he chronicles in his book how he was shot at -- but in the end he was pleased he didn't because he believes talking and politeness can solve most any problem.
Salopek says "you make yourself vulnerable when you're on foot," but that he won't carry a gun. He has security procedures in place that he can't share, he said. He knows he may have problems at some borders -- Iran, for instance -- but plans to solve problems when they crop up, relying heavily on "adaptation and serendipity" just as our ancestors did.
The first part of the journey will take Salopek across the Ethiopian desert, so while he was still at home earlier this month he sent a money order from a Texas Walmart to the tiny East African nation of Djibouti to buy a camel that will help him carry water.
Carrying little more than a backpack with a lightweight Apple laptop, a satellite phone and camping gear, Salopek plans to send occasional updates via Twitter. On Jan. 2 he posted a picture on Twitter of the keys to his house in Texas and wondered if he should pack them. He has decided not to tell.
"Maybe I should keep that as a secret," he said over the crackly satellite phone connection. "Let's just say that only I know what's in my pocket."