Wellington: New Zealand Prime Minister Jacinda Ardern appeared awestruck Thursday to be standing in the Antarctic hut of explorer Ernest Shackleton. “I think when you’re a kid and you read stories about Shackleton, you’d never imagine you’d have the opportunity to come. So, I feel pretty lucky,” she said from inside the hut that was built more than a century ago. “It’s a cool place.” Ardern this week is making a rare visit by a world leader to Antarctica, to see firsthand the research taking place on global warming and to mark the 65th anniversary of New Zealand’s Scott Base,...