A playful-looking giant panda cub, lying on its back with its paws in the air. A flock of migrating sandhill cranes, white clouds billowing around them, as seen from their same high altitude. A mountain stream choked with pandemic-killed frogs, a spotted owl perched in a clearcut forest, the gleaming brown eyes of an ocelot. They’re some of the many images by award-winning National Geographic photographer Joel Sartore, who speaks March 26 at The Ohio State University. It’s a kickoff to the university’s ongoing celebration of Earth Day in April.