Astronomers from the University of Virginia and other institutions have found that Enceladus, the sixth-largest moon of Saturn, is a “cosmic graffiti artist,” pelting the surfaces of at least 11 other moons of Saturn with ice particles sprayed from its spewing surface geysers. This ice sandblasts the other moons, creating a reflective surface that makes them among the brightest bodies in the solar system (Enceladus, itself a ball of mostly ice, is the single most reflective body in our solar system).

“Enceladus’ art is a work-in-progress, constantly altering the surfaces of other moons orbiting within this moon’s beautiful swirl of ice particles,” said Anne Verbiscer, a research scientist in the astronomy department at the University of Virginia and the study’s lead investigator.

Physicists at the Commerce Department's National Institute of Standards and Technology (NIST) have taken the first ever two-dimensional pictures of a "frequency comb," providing extra information that enhances the comb's usefulness in optical atomic clocks, secure high-bandwidth communications, real-time chemical analysis, remote sensing, and the ultimate in precision control of atoms and molecules.

Four million people die every year from respiratory diseases such as viral influenza. For elderly people in particular, an infection can be dangerous. What is more, the flu vaccine is not as effective with this risk group as it is with younger people. The reason for this is that with age the fire power of the immune system is reduced. Why this is the case is largely unknown. An international EU project led by the University of Bonn is now starting which aims at shedding light on this. Among other things, the researchers want to get a step closer to solving this riddle by examining tens of thousands of blood samples.

An international team of scientists has discovered that the ubiquitous bacteria that causes most painful stomach ulcers has been present in the human digestive system since modern man migrated from Africa over 60,000 years ago. The research, published online (7 February) by the journal Nature, not only furthers our understanding of a disease causing bacteria but also offers a new way to study the migration and diversification of early humans.

As the second leading cause of death in the world, cigarette smoking is a preventable behavior. Most countries require warnings about health risks on every package, but the effectiveness of these warnings depends upon the design and the "freshness" of the messages. In a multi-country study published in the March 2007 issue of the American Journal of Preventive Medicine, researchers found that more prominent text messages were more effective and graphic pictures even more so in affecting smokers' behaviors.

Researchers have constructed a protein out of amino acids not found in natural proteins, discovering that they can form a complex, stable structure that closely resembles a natural protein. Their findings could help scientists design drugs that look and act like real proteins but won't be degraded by enzymes or targeted by the immune system, as natural proteins are.