Penetrating the orange haze of a frigid, alien world, a space probe parachuted onto Saturn's moon Titan and unexpectedly came face-to-face with terrain that looks a lot like Earth. (p. 51)

Fossils unearthed at sites in eastern Africa provide a rare look at Ardipithecus ramidus, a member of the human evolutionary family that lived more than 4 million years ago. (p. 51)

Astronomers have found the first evidence of a suspected population of black holes near the Milky Way's center, each hole with 10 times the mass of the sun. (p. 52)

European green crabs invading a California bay have triggered a population explosion of a previously marginal clam. (p. 52)

The vision of flexible, low-cost, lightweight plastic solar cells has moved one step closer to reality with the creation of a material that can harness infrared light. (p. 53)

A new breed of mobile micromachine made of living heart tissue, gold, and silicon takes a step with each rhythmic contraction of its muscle cells. (p. 53)

On Jan. 14, the Bush administration announced a $37.5 million program to expand the nation's tsunami-warning capabilities. (p. 54)

New evidence suggests that supermassive black holes have an impact on the evolution of galaxies that goes far beyond their gravitational grasp. (p. 56)

A firsthand account unveils the pageantry that surrounds the awarding of the Nobel prizes in Stockholm. (p. 59)

Brain areas already implicated in the use and comprehension of spoken language play comparable roles in the whistled messages of shepherds living on an island near Spain. (p. 61)

A California survey indicates that the practice of allowing babies and toddlers to sleep in the same bed as their parents do occurs in two forms, each with its own implications for the quality of family sleep and the children's psychological development. (p. 61)

Scientists have unveiled a root cause for why hair goes gray. (p. 61)

Pregnant women who breathe polluted air deliver babies that are typically slightly smaller than those born to other mothers. (p. 61)

Long-lived sperm whales typically develop bone damage not previously observed in marine mammals but found in some human divers who surface quickly or dive frequently. (p. 62)

Chemists have created miniature engines out of nanoscale metallic rods that propel themselves using chemical energy. (p. 62)

New X-ray observations provide the most detailed view yet of the environment near a supermassive black hole. (p. 62)

The dusty disks surrounding three nearby stars show that they played host to massive collisions between asteroid-like objects as recently as 100 years ago. (p. 62)

(p. 63)