One of two long-lost British explorer ships that mysteriously vanished in the Arctic in 1846 was recently discovered, Canada's prime minister announced Tuesday, possibly solving one of history's biggest puzzles.

Last seen in the 1840s while under the command of Sir John Franklin, both the HMS Erebus and HMS Terror have long been considered a lost cause, until Canadian researchers using a remotely controlled underwater vehicle discovered the well-preserved wreck of one of the vessels Sunday. (Scroll to read on...)

Located 11 meters (36 feet) below the icy Arctic surface lay one of those famous ships, though which one, to be exact, is still unclear.

But, the discovery could be the key to unlocking one of history's biggest mysteries.

"This is truly a historic moment for Canada," Harper told The Associated Press (AP). "This has been a great Canadian story and mystery and the subject of scientists, historians, writers and singers, so I think we really have an important day in mapping the history of our country."

Harper is now confident that the second ship is not far behind.

"Finding the first vessel will no doubt provide the momentum - or wind in our sails - necessary to locate its sister ship and find out even more about what happened to the Franklin Expedition's crew," he told the AP.

Franklin and a crew 128-strong set out in 1846 to find the Northwest Passage, the long-sought shortcut that linked the Atlantic and Pacific Oceans. Historians believe that as the vessels sailed farther into the Arctic archipelago, the crew became trapped in ice for a year and half, eventually dying from extreme cold, starvation, or cannibalism.

Researchers have tried and failed over the years to locate the HMS Erebus and HMS Terror, finding clues here and there but mostly coming up empty. Just in 2008, Canada announced a renewed determination to find the ships, pouring millions into the endeavor.

Now, with this incredible discovery, experts can start to unravel the mystery behind this ill-fated, mid-19th century voyage and its significance in history.

"On the one hand, it's an achievement, but on the other hand it's a beginning," Jim Balsillie of Research in Motion, who is involved in the Canada-led search, told CBC News.