It was that time of year in Antarctica when the sun peaked in the sky just above eye level, then dipped below the horizon again a mere three hours later. He walked with the midday sun at his back, crossing a snow field, ducking to fend off the pellets of snow and ice that assaulted him with each gust of wind. His thick red parka and extreme-weather gear gave little comfort in this cold. But he trudged on, knowing it would be worth it, even if he got caught in the end. His assignment would last just two more weeks anyway. After that the conditions would be unbearable, even for one of NASA’s most battle-scarred field scientists. He had been tasked with studying ancient microbes in the ice, and learning how and why they were able to survive for millions of years in this environment when he couldn’t make it…