"Hello? Are you still there?" Anybody who has experienced a momentary disruption in a cell phone conversation knows that the first task is to verify that the other party is still on the line. Researchers in the pursuit of evidence for extraterrestrial intelligence (SETI) have found themselves on the tantalizing brink of making what appears to be first contact on a number of occasions, only to be unable to verify that they have found a real signal--that is, someone at the other end of the line. 

In the name of science, researchers have fashioned numerous kinds of mice: fat, thin, hairless, or afflicted with a particular disease, to name a few. Now the first draft sequence of the mouse genome should make the tiny rodents even more helpful for future research into a variety of diseases. The findings indicate that mice and humans have a similar number of genes (around 30,000) and that nearly 90 percent of genes associated with disease in people have counterparts in mice. 

Science writer Powell casts science as the new religion, with Einstein as god. "Sci/religion," as he calls it, "offers a positive and immensely appealing alternative way to look at the world, a religion of rational hope." Even if you disagree with Powell's premise, his book is a delight to read - lively, well informed, personable. And as a bonus, it provides an unusually graceful account of the history of cosmology. 

Most current methods for cooling things down require the use of chemical refrigerants. Perhaps the most famous of these are CFCs, which destroy the ozone layer and were banned in 1996. Although the replacement gases don't affect the ozone layer, many of them still affect the environment because they are potent greenhouse gases. New research suggests that these cooling chemicals in your freezer may one day be replaced by harmless sound waves.

Visitors to high-elevation locales often experience difficulty breathing because the amount of oxygen available in the atmosphere decreases with increasing altitude. In extreme situations, altitude sickness can be fatal. But people born and raised at high altitudes function well despite the reduced availability of oxygen. Researchers have found that residents of a high-altitude village in Ethiopia have a unique way of adapting to the lower levels of oxygen at high elevations.

Current models of solar system evolution posit that a planet of Jupiter's size and scope would need more than a million years to form. But scientists have discovered close to 100 similar giant planets orbiting nearby stars, which suggests that they are more plentiful than would be expected if they had such a long gestation period. New findings may help account for the relative abundance of these gas giants. They may take shape much more quickly than previously thought.

Randall K. Packer, a professor of biology at George Washington University, explains.