Understanding estrogen's function is complicated by the fact that it can bind to two distinct receptors; scientists studying the second receptor now think that drugs targeting it could help a wide variety of ailments. (p. 8)

A distant galaxy is shooting a deadly jet of radiation at a neighboring galaxy, astronomers have observed. (p. 388)

Little progress has been made this decade in reducing the size of the Gulf of Mexico's dead zone, a massive area of oxygen-depleted water caused by agricultural and urban runoff. (p. 395)

The Venus Express probe has found evidence that Venus once had more water than it does today, and has provided new measurements of the weather on Venus, proof of lightning on the planet, and signs of a formerly unknown hot spot near its south pole. (p. 339)

Nigersaurus boasted more than 500 teeth, arranged in rows across its mouth. (p. 325)