Watch: What Is an Explorer in the 21st Century?

A hundred years ago, one of the last great polar expeditions—the grandly named Imperial Trans-Antarctic Expedition—went seriously awry 80 miles off the coast of Antarctica when packs of sea ice crushed the explorers' wooden boat, called the Endurance. Expedition leader Ernest Shackleton managed to rescue his men after a two-year saga, which to this day is one of the greatest survival epics ever recorded.

[Related: The Big Melt: The Last Antarctic Explorers Are Seeking Answers Inside the Continent's Ice]

In December, I went down to Antarctica for Newsweek, sailing 40 hours from the tip of Argentina on a modern, ice-cutting cruise ship to commemorate the Shackleton expedition and try to find out what "exploration" means in the modern era. I brought with me lawyer-explorer Charlie Wittmack, and together we interviewed the ship's captain and crew, on-board naturalists and fellow passengers about what makes someone an explorer in an age when the world is fully mapped and so much of it safely accessible.

We conducted the interviews on board a metal-hulled former Norwegian coastal ferry called the National Geographic Explorer equipped with the latest sonar, radar and communications equipment, as we crunched our way through ice-choked bays and channels around the glorious and strange Antarctic Peninsula—a piece of a continent that's been described as the closest thing to Mars we have on Earth.

In this short video, produced and directed by Wittmack, we share some archival photographs from the Shackleton expedition, gorgeous icebergs and penguins that we found on our own journey, and surprising answers our captain, crew and fellow passengers gave to the question, What is an explorer in the 21st century?