LIMA, Peru (AP) _ A Lima university conferred an honorary doctor's degree on Norwegian explorer Thor Heyerdahl to mark the 50th anniversary of his ocean voyage in the balsa wood raft Kon-Tiki.

Heyerdahl sailed from Lima's sister port of Callao in 1947 to prove the first Polynesians could have crossed the Pacific from South America, and not from Asia as the conventional wisdom held at the time.

He and a crew of five spent 101 days at sea on a voyage of 5,000 miles before reaching the atoll of Raroia in French Polynesia.

Lima's Federico Villarreal University awarded the degree to the 83-year-old Heyerdahl during a ceremony Wednesday at the National Institute of Culture.

Heyerdahl was also honored in the evening with a medal from the Peruvian Institute of Maritime Historical Studies.

The explorer is currently carrying out investigations on the northwestern coast of Peru, site of the ancient Chimu and Moche cultures.