Until Virgin Galactic starts offering bargain fares on its space flights, the continent fondly referred to as "the Ice" is the closest we'll get to visiting another planet. More tour operators are voyaging south, but go with a responsible outfitter like Intrepid Travel. On its new ten-day Antarctic Peninsula trip, you'll make a two-day crossing from Argentina on the 100-passenger, icebreaker-class M/V Polar Star, spend three days on the continent, walking with penguins and watching whales from Zodiacs, and then catch the South Shetland Islands on the return (from $5,260; five trips from November to March; intrepidtravel.com). Wanna sweat a little? Try summiting Antarctica's highest peak, 16,067-foot Vinson Massif, with RMI mountain guide Dave Hahn. He's been up Everest 12 times, Vinson 27 (rmiguides.com).