A New Mars
At the recent thirtieth anniversary celebration of the Viking mission, Gentry Lee discussed the excitement of landing on Mars for the first time, and how far we�ve come in our exploration of Mars since then.

Reweaving the Food Web
The recovery of biodiversity after the end-Cretaceous mass extinction was much more chaotic than previously thought, according to paleontologists. New fossil evidence shows that at certain times and places, plant and insect diversity were severely out of balance, not linked as they are today.

Sneezing in Space
When space shuttle Atlantis next rockets into space, it will take along three kinds of microbes so scientists can study how their genetic responses and their ability to cause disease change.

Even Single Cells Stick Together
New research published by Rice University biologists in this week's issue of Nature finds that even the simplest of social creatures - single-celled amoebae - have the ability not only to recognize their own family members but also to selectively discriminate in favor of them.

Sulfur Stinks up Oxygen Theories
Ancient sediments that once resided on a lake bed and the ocean floor show sulfur isotope ratios unlike those found in other samples from the same time, calling into question accepted ideas about when the Earth's atmosphere began to contain oxygen, according to researchers from the U.S., Canada and Japan.

Water is Essential for Bonding at RNA Parties
Researchers at the University of Michigan and the Academy of Sciences of the Czech Republic have uncovered two previously unknown roles for water in RNA enzymes, molecules which themselves play critical roles in living cells.

Calendrical Bacteria
Every creature has its place and role in the oceans - even the smallest microbe, according to a new study.

Is Functional RNA the Missing Link?
Scientists have discovered a gene that has undergone accelerated evolutionary change in humans and is active during a critical stage in brain development. Although researchers have yet to determine the precise function of the gene, the evidence suggests that it may play a role in the development of the cerebral cortex and may even help explain the dramatic expansion of this part of the brain during human evolution.

The Sun in STEREO
NASA's STEREO mission to study the sun is set to launch August 31. During the two-year mission, the spacecraft will explore the origin, evolution and interplanetary consequences of coronal mass ejections, some of the most violent explosions in our solar system. When directed at Earth, these eruptions can disrupt satellites, radio communications and power systems. Energetic particles associated with the sun's eruptions permeate the entire solar system and may be hazardous to spacecraft and astronauts.

The Ammonia-Oxidizing Gene
Archaea may play a larger role in the nitrogen cycle than previously thought. A recent genetic analysis of soil samples indicates that crenarchaeota are the most abundant land-based creatures to oxidize ammonia. Combining ammonia with oxygen forms nitrates, which are used as nutrients by plants.