How flames spread, not how frequently people start them, controls burning on the continent. (p. 14)

Sulfur and silicon may be more abundant in the planet’s heart than thought.

Even an Iron Chef couldn’t master what a food-centric cadre of NASA scientists do every day: Devise tasty, healthy meals for astronauts to take into low-Earth orbit and beyond — perhaps even to Mars. Feeding people in space is harder than it sounds. Meals have to contain enough nutrients to keep the human body functioning in near-zero gravity. Slicing, dicing and stir-frying are impossible because ingredients float around. And now that NASA has set its sights on manned trips to Mars, packaged food has to last longer than ever to keep dinner from spoiling (SN Online: 7/26/10). Fortunately... (p. 20)

A mammal fossil unearthed in South America resembles ‘Ice Age’ saber-toothed squirrel. (p. 12)

SOCORRO, N.M. — Ten thousand feet high in the New Mexico mountains, Jake Trueblood is getting ready to fire rockets into a thunderstorm. He lines up eight rockets, straight as soldiers, then connects each to a wire bobbin once used to guide missiles for the French military. Trueblood arms the rockets and heads underground, then waits for hours in a windowless chamber on whose metal roof the rockets sit. Trueblood, a graduate student at the New Mexico Institute of Mining and Technology in Socorro, is waiting for a good strong electric field in the atmosphere. Then he’ll push a button that... (p. 16)

Satellite data confirm that the amount of forest cover can shift suddenly in response to relatively small changes in fire frequency and rainfall. (p. 5)