carl zimmer’s enduring fascination with dinosaurs began when he was 4 years old and has deepened ever since (“Dinosaurs,” page 32). “Over the years, you can see some of the same questions popping up again and again,” he says. “The toughest questions to answer are usually the ones that involve nature at its biggest scale.” Zimmer’s latest book, Soul Made Flesh, about the 17th-century discovery that the gray matter in our skulls is the locus of human wisdom, was named one of the 100 notable books of 2004 by The New York Times Book Review.

This is the second time that photographer ferit kuyas has covered a European Space Agency mission for Discover, but this story (“News From Earth’s Wayward Twin,” page 40) had a happier ending. Two years ago Kuyas worked on a feature about Mars Express, which lost its Beagle 2 probe. This time he was present at mission control in Germany when the Huygens probe landed on Saturn’s moon Titan and provided the first glimpses of an alien world. “It was fascinating to witness something extremely spectacular and groundbreaking,” Kuyas says.

CHRISTOPH NIEMANN has been illustrating the R&D Ask Discover column (page 14) for the last six months and likes the variety. “There’s always a new topic for me to have fun with and find metaphors for,” he says. His work has also graced the covers of The Atlantic, The New Yorker, and The New York Times Magazine. 100% Evil (Princeton Architectural Press), a book of illustrations by Niemann and Nicholas Blechman, arrives in bookstores this month.

JOSHUA FOER first heard about the movement to replace the Linnaean system for classifying species (“Pushing PhyloCode,” page 46) in his undergraduate mammalogy class at Yale University last year. “You can’t do biology without naming things, so it’s immensely important,” he says. “There might be a right or wrong in the sense that one convention is better than another. But there’s not necessarily an objective right or wrong.” Foer has written for The New York Times, The Washington Post, and Slate.