James Cook and the Transit of Venus

“On August 12, 1768, His Majesty’s Bark Endeavour slipped out of harbor, Lt. James Cook in command, bound for Tahiti. The island had been “discovered” by Europeans only a year before in the South Pacific, a part of Earth so poorly explored mapmakers couldn’t agree if there was a giant continent there … or not. Cook might as well have been going to the Moon or Mars. He would have to steer across thousands of miles of open ocean, with nothing like GPS or even a good wristwatch to keep time for navigation, to find a speck of land only 20 miles across. On the way, dangerous storms could (and did) materialize without warning. Unknown life forms waited in the ocean waters. Cook fully expected half the crew to perish. It was worth the risk, he figured, to observe a transit of Venus.”