Enjoying EarthSky? Subscribe.

Darryl Granger was a member of the 2010 expedition to Hang Son Doong, led by British explorers Howard and Deb Limbert. He is a professor of Earth and Atmospheric Sciences at Purdue University. Dr. Granger has 15 years of caving experience. Granger developed a dating method that, in 2009, allowed a more accurate determination of the age ot the remains of Homo erectus, commonly known as “Peking Man.”