Cloud-borne bacteria may be to blame for rain, snow and hail because they affect the way water molecules bind. Does that mean snowballs are germ warfare?

Trials of two different drugs show promise in treating advanced melanoma, which is usually fatal.

NASA finds “a significant amount” of water on the moon, heightening the practicality of a future lunar base just as the space shuttle program draws to a close.

The Milky Way may contain many billions of stray, Jupiter-size planets that were kicked out of their solar systems and left to wander space on their own. This would mean there are many, many more planets than stars, making earthlings even more insignificant.

The World Health Organization issues a finding that cell phones are “possibly carcinogenic.” An informal visual survey in New York City shows no apparent reduction in use.