Scientists using a Mars-orbiting camera have found the first evidence for deposits of salts in numerous places on Mars. These deposits show where water was once abundant and may also provide evidence for the existence of former Martian life. --by Robert Burnham

"Beowulf is an existential poem. It offers insight into a whole social structure," explains Robert Bjork, director of the Arizona Center for Medieval and Renaissance Studies. "But it also takes you into the existence of the individual. And it’s a poem without real resolution." Bjork thinks the poem should be viewed as a retrospective nostalgic look at a pagan past through a sympathetic, Christian present. --by Sheilah Britton

Do TV shows like CSI taint jurors' perceptions of forensic evidence? For years, legal professionals and the mass media have claimed that a "CSI effect" is influencing jury trials. But these claims aren't backed up by real data. In fact, new research from ASU indicates that watching CSI doesn't make people any more or less likely to convict. --by Diane Boudreau

Nitrogen pollution from agricultural and urban runoff is a serious threat to ocean ecosystems. Nitrogen, in the form of nitrates, could generate algal blooms, create oceanic "dead zones" and kill coral, fish and shellfish in coastal zones. Researchers have discovered that small organisms in streams and rivers can filter out excess nitrogen before it reaches the oceans. However, overloading streams with too many nitrates reduces their filtering ability. --by Margaret Coulombe

Scientists have developed a method that extends the power of fluorescence-mediated bioimaging to see discrete pigments inside live cells of bacteria. The method is providing fresh insights into what happens on a molecular level during photosynthesis. It also promises to provide important information about the inner workings of cells as they engage in the process of collecting sunlight and turning it into chemical energy. --by Skip Derra

To humans, trichloroethene (TCE) is a dangerous pollutant, one that recently forced two Phoenix-area municipalities to shut down their water supplies. But to a group of bacteria called dehalogenerators, TCE is like oxygen. These microorganisms take in TCE and remove the chlorine, leaving harmless ethene behind. Now a team of scientists has developed a specialized water treatment system that employs the bacteria to make water supplies safer. --by Joe Caspermeyer

Scientists have long known that most compounds in living things exist in mirror-image forms. The two forms are like hands; one is a mirror reflection of the other. But amino acids, which are the building blocks of proteins, are all "left-handed," while the sugars of DNA and RNA are "right-handed." ASU scientists have found new evidence that extraterrestrial amino acids, found in meteorites, are also largely left-handed. Their work suggests that precursor molecules, the aldehydes, also carried an excess of left-handedness. --by Jenny Green