Astronomy Second look finds no comet reservoir Last year, astronomers hailed Hubble Space Telescope's detection of about 30 faint, comet-sized bodies in a vast reservoir known as the Kuiper belt. However, a second look with the telescope has failed to show evidence of these faint objects. Computer simulations suggest that some large groupings of galaxies, known as superclusters, may be less tightly packed and don't arrange themselves in the concentric pattern that some maps indicate. After linking the activity of a gene to that of the gene that makes fireflies and other glowing organisms shine, investigators can monitor genetic activity in a single living cell by recording pinpricks of light. The gene that keeps plants off Geritol Scientists find a gene that enables plants to make the most of iron-poor soil.
Paleontologists explore the early history of cetacean evolution.
Telling time 400 million years ago Two researchers have developed a type of magnetic stopwatch for timing evolutionary and geologic events far back in Earth's history. Scientists are trying to decipher the signals that nerve cells in the body use to encode information and coordinate activity. The next half century promises unprecedented challenges As Earth's population swells, researchers are attempting to identify and cope with some of the major factors that will determine how many people our environment can sustain.