Scientists have analyzed a "light echo" from the original explosion of Cassiopeia A, the youngest known supernova in our own Milky Way galaxy.

The explosion occurred around 1680 -- just yesterday, in stellar terms.

The scientists observed an infrared spectrum of radiation that suggests Cassiopeia A was a type IIb supernova and was birthed from the collapse of a red supergiant star.

Many bees, ants and wasps live together in highly cooperative societies primarily because this lifestyle offers a good way of passing down the family genes, not because it makes their own lives easier, new research suggests.

Scientists compared the mating behavior of females in 267 species of bees, wasps, and ants. They found that in the older species, females were always monogamous.

This finding supports the idea that monogamy - and, by extension, a high level of relatedness -- was key to the evolution of eusociality (many animals live together as a group without necessarily being social).

How to beat jet lag: don't eat, researchers suggest.

In addition to the light-driven circadian clock that regulates the body in response to changes in night and day, the mouse brain contains a second, separate clock that keeps track of mealtime, scientists say.

This clock, which resides in a different brain structure than the light-driven clock, probably takes over when food is scarce, changing the animals' behavior patterns so that they don't sleep through an opportunity to eat.

NASA's Spirit rover has detected silica-rich deposits on Mars, researchers reported in a study that provides the data and analysis underlying this discovery.

Extensive deposits of nearly pure silica – either as quartz or opal – are typically signs of geochemical processes that involve water.

The findings lend support to the idea that relatively large amounts of liquid water once existed on Mars.

A particular type of shorebird (Phalarope) exploits the physical properties of water to transport water droplets to its mouth and feed on the tiny creatures contained within, researchers say.

Because of the shape of its beak, the bird cannot suck the water all the way up to its mouth. What it does instead is quickly open and close its beak many times like a pair of tweezers, and the water actually moves up the long beak — against the pull of gravity — and all the way to the phalarope's mouth.

This action is made possible because of something called "surface tension." It is the first time that scientists have documented this particular way of eating.

Small primates like squirrel monkeys and lemurs expend no more energy climbing than they do walking, according to a new study.

On the other hand, the energy required for a primate to walk in a straight line actually decreases as the primate's size increases, which implies that it makes more sense for larger primates to stay on the ground while, metabolically, it does not matter if smaller primates walk or climb.

The findings may explain the evolutionary edge that encouraged the tiny ancestors of modern humans, apes and monkeys to climb into the trees about 65 million years ago and stay there.

For their experiment, researchers designed and built a novel climbing treadmill -- essentially a loop of rope around two pulleys -- to measure the animals' efforts. As the animals moved at their highest sustainable speed, sensors measured oxygen level changes within a chamber to derive the primates' energy consumption.

Salt causes the deterioration of historical artifacts
Scientists are fine-tuning the composition of cellulose poultices to maximize the extraction of salt from historical monuments.

The porosity of the various materials used throughout history to construct buildings and sculptures make them susceptible to salt absorption at rates which vary depending on geography, temperature, weather, and soil.

Salt carried by water and moisture are absorbed into the materials and deposited deep into the structures once the water evaporates. Over time, the salt reacts with the materials and compromises their strength and accelerates decay.

In a study of mice, where animals breathed air as polluted as the air in New York City, researchers showed that urban pollution may be as dangerous or even more dangerous than breathing second-hand smoke.

Artist's impression of HD 189733b

By identifying the "chemical fingerprints" -- organic molecules found in a planet's environment -- scientists can begin to locate "habitable zones" in exoplanets (planets outside our solar system). These zones are defined by their chemical composition, temperature, and pressure, all of which are necessary for the possibility of life.

The detection of water and methane in the atmosphere of the Jupiter-sized gas giant, HD 189733 b, may open the door to a deeper and more localized analysis of other more promising exoplanetary environments, scientists say.

Scientists have enlisted the public's help in the photo identification of whale sharks, the world's largest fish. Divers are encouraged to submit any photos they take of whale sharks to a Web site (whalesharks.org) that tracks the endangered whale sharks around the world. Despite their giant size, whale sharks are harmless to divers and snorkelers. The patterns of spots on their backs are unique to each individual.