New research confirms that alpha particles from decaying radon atoms can damage neighboring cells they don't directly hit and suggests a mechanism for this so-called bystander effect. (p. 356)

A costly accident has indefinitely disabled Super-Kamiokande, a cutting-edge neutrino detector in Japan. (p. 327)

The newly operating Gemini Multi-Object Spectrograph instrument on the Gemini North Telescope on Mauna Kea, Hawaii, took a high-resolution composite photograph of a galaxy 30 million light-years away. (p. 228)

A crippled NASA probe successfully navigated close enough to Comet Borrelly to capture and beam home black-and-white and infared images of its nucleus and new data about ions and other particles that radiate from it. (p. 196)

The first discovery of early whale fossils with key ankle bones intact provides compelling paleontological evidence that whales are closely related to many living ungulates, a relationship already supported by molecular data. (p. 180)

The round goby, a Eurasian fish that has invaded the Great Lakes, is causing the decline of the mottled sculpin by displacing the native from its spawning sites. (p. 166)