These are tense times for scientists and engineers at NASA's Jet Propulsion Lab in Pasadena. Late Sunday night Pacific Time, they'll learn if nearly a decade of hard work will result in a priceless scientific laboratory landing safely on Mars or if the rover known as Curiosity will turn into a useless pile of junk. Everything depends on what happens during the seven minutes of terror, the time it takes the probe to go from the top of the Martian atmosphere to the planet's surface.
It turns out the Later Stone Age wasn’t quite so late. A University of Colorado archeologist has just completed a new analysis of artifacts that has pushed the period back by 20,000 years. The work may resolve one of the long-running paradoxes of human history—but in the process, it has created a new one.