10 questions for Torgeir Higraff, the Kon-Tiki2 Expedition leader, by Håkon Wium Lie.

Why do this?

Kon-Tiki2 got its name because we seek to double-down on Thor Heyerdahl's famous voyage by sailing two rafts from South America to Polynesia and then back! No one has done this in modern times, and we will prove that it can be done. It's an unparalleled voyage of survival, science and exploration.

Did people sail the Pacific both ways in the past?

Scientists have recently published an article showing that Easter Islanders have some Native American DNA in their genome (Genome-wide Ancestry Patterns in Rapanui Suggest Pre-European Admixture with Native Americans). The moment of first contact has been dated to between AD 1300 and AD 1500 – well before the arrival of the first Europeans.

Does the DNA evidence prove Thor Heyerdahl's theory – that Polynesia was settled by South Americans?

Other DNA studies have shown that the prehistoric origin of the Polynesian people is in Taiwan. We're not challenging this, but I believe – like Heyerdahl – that oceans were communication routes and not impossible barriers. Through Kon-Tiki2, we will learn more about how those communication routes could have been used.

Why is this important?

In order to understand human migration in the Pacific, it is essential to know what sea voyages were possible. While Heyerdahl demonstrated successfully that sooner or later currents naturally would carry a raft to parts of tropical Polynesia, effective steering and tacking systems would have been essential for South American mariners to sail towards specific destinations like Easter Island, and then find their way back to their beloved ones against the winds. It's about time to present how sophisticated the rafts where – far more than just traveling with the current. Today, perhaps the most pertinent question is not "Did contact occur?" but "Who was contacting whom? – And how?"

Kon-Tiki2 makes the ancient Pacific a pathway for both Polynesians and South Americans. We know both cultures had rafts, Polynesians probably used their superior double hulled canoe for exploration and rafts for migrations. We will show how Polynesians sailed to South America (Polynesian chickens were found in Chile) and back, and how South Americans did the same in the opposite order.

Was there a maritime culture in South America that could build and sail rafts similar to the ones Kon-Tiki2 will use?

Yes, several cultures – and for thousands of years. First, recent research shows that the Peruvian coastline is one of the cradles of civilization. The Norte Chico culture which flourished there dates almost 5000 years back in time and was probably more dependent on seafood and maritime resources than agriculture.

Second, The Manteño were an Ecuadorian maritime culture that began around AD 800, and ended in AD 1526, when the Spanish Conquistadores arrived. The Manteño were a "league of merchants," using balsa wood raft to become a rich trading society.

Third – and at the same time – the maritime Sicán culture emerged on the northern Peruvian coast after the Moche collapse. The Late Sicán polity was conquered by the Chimú Kingdom around AD 1375, which, in turn, was conquered by the Inca by AD 1470. The rulers from the mountains, the Inca, inherited and took advantage of the coastal maritime expertise. They had to, in order to keep expanding their empire. At least three separate Spanish chroniclers independently recorded the same basic story from around 1480: Tupac Yupanqui had emerged victorious at a major maritime battle in present day Ecuador. Eager to extend his reach, he spoke to some visiting merchants from the west who told him about the far-away islands from which they came and from whence they made frequent trips to South America. To find these islands, Tupac Yupanqui set sail with his huge fleet of balsa rafts, with a crew of thousands of men, into the Pacific. Somewhere between nine months and a year later, they returned to the continent and recounted their discovery of two inhabited islands previously unknown to the Inca.

Now, we don't know the identity of the "merchants from the west," or what islands the Inca visited. But the new scientific evidence of DNA-contact certainly reopens the idea that Easter Island was one of them. The Kon-Tiki2 expedition can neither prove nor disprove what happened in 1480, but we can show that such balsa raft voyages would have been possible with rafts the Incas, and people thousands of years before them, could build.

What else makes the Pacific expedition important today?

Some tuna species and a quarter of the world's sharks are threatened with extinction. Overfishing is the main threat to the species. But also plastic is threat to the life in the oceans. Our sailing route from Easter Island to South America is extremely interesting for scientific water pollution studies. We will be sailing in the Southern Pacific Garbage Patch, discovered only few years ago, where little research on marine plastic pollution exists. Also, The Peruvian Current has never before been mapped for plastic and molecular pollution. The balsawood rafts are perfect platforms to make people aware of this giant environmental problem.

Are there other reasons for going on a raft voyage?

The sense of adventure is compelling for everybody in the crew. If you read about the crew, they also express a longing towards reaching new shores in untraditional ways. Or, perhaps, reaching old shores in very traditional ways. Many of us grew up with tales of Thor Heyerdahl's achievements, and we, too, long for the worlds he explored.

Is there something for the present day digital people to learn?

One of our sponsors, Opera Software, is experimenting with digital survival over very thin communication lines. Many of us depend on everyday broadband connections, but what happens when you are stuck with an ultra-narrow-band connection for six weeks? Remember, most people on this planet do not have access to a broadband internet. Is it still possible to live your life, and perhaps even contribute to our digital world? We shall see.

What else did the South Americans use the rafts for?

The Manteños were extremely skilled at diving for the shells and they had the giant balsa rafts to transport their goods. At its height, the Manteño culture spanned the entire coastline of ancient Ecuador. In 1526, Manteño mariners encountered an unusual ship off the coast. The Spaniards recorded this fateful meeting at sea in their logs and diaries, stating that the raft was a freighter from the port of Salango. It carried gold, silver, fine cloth, and spondylus. These shells were as precious as gold, found in the graves of kings back to the Moche era. The Spanish seamen noted that the raft "carried sails like that of our own ships", and that the raft was sailing north on a trading voyage. Within ten years of this first meeting, the Inca Empire had fallen, ninety percent of the Manteño had died of European disease, and the Spanish Empire controlled the Pacific Coast.

So, the rafts had good sails, but how did they steer?

Along the coast that was controlled by the Chincha people (1300 - 1500) archaeologists have found hundreds of wooden boards in graves. Typically, these are 150-200cm long boards made from hardwood. In the past 100 years, archaeologist and collectors have put them on display in numerous museums and one is displayed in the Metropolitan Museum of Art. Thousands, maybe millions of people have stopped by the wooden boards, reading "ceremonial staffs," "funerary staffs", "wooden sculpture", or some other strange explanation. These are actually centerboards used to steer rafts, called "guares" by the conquistadors. We will use them in our expedition to travel safely to Easter Island. And back!