Saturn's rings may be antique

Saturn's rings may be vintage jewelry as old as the solar system, and they're practically sparkling with water ice.

The findings, based on data from NASA's Cassini spacecraft and released in the Astrophysical Journal, give planetary scientists a window into the solar system's birth and development, and show that the formation of at least one of the planet's 62 known moons may have been a little more complicated than thought.

Launched in 1997, the Cassini mission spacecraft is now on its third lifetime exploring Saturn's complex system and still turning up remarkable new information about the ringed gas giant. Data from the spacecraft's visual and infrared mapping spectrometer have revealed how water ice and shades of color are spread through Saturn's system. Finding an abundance of water ice — too much to have been deposited by icy comets ramming into the planet or its moons — the team of Italian and American scientists realized that the ice must hail from around when the solar system first formed, more than 4 billion years ago.

The researchers came across one big surprise: Prometheus, Saturn's long moon, shares a reddish hue with some nearby ring particles — even though the surrounding moons are all white-toned. Perhaps Prometheus was created from the ring particles, they said. Astronomers generally believe that Saturn's rings are formed from the smashed up remains of larger bodies. But it now seems that moon creation and destruction could be a two-way street.

distinction for whales in gulf?

The Gulf of Mexico's isolated population of sperm whales may be different enough from sperm whales worldwide to qualify for protections under the Endangered Species Act — a designation that would boost scrutiny of human activities that could harm the species, including oil and gas development, ship traffic and use of chemicals.

The National Marine Fisheries Service said it will consider separately listing the Gulf's sperm whales as threatened or endangered. The announcement begins a 12-month timetable for study.

The regulatory push comes after research since 2000 has shown that the Gulf's sperm whales are genetically different from those found in other oceans. While sperm whales in general are listed as endangered, the distinction means the federal government may require additional safeguards to protect the estimated 1,300 sperm whales in the Gulf.

The government lists six species of whales as endangered in the Gulf, including the blue and humpback, but only the sperm whale congregates year-round. They also are smaller in size than sperm whales found in other oceans.

finding plants' sweet spot

Even plants like a sugar rush. Or so researchers have discovered while studying the sweetness of sap, which carries sugars from a plant's leaves to other locales, such as the roots.

Plants face a tricky balancing act as they load sugar into their sap. Sap with too much sugar is too thick to flow easily, but sap with too little sugar makes for inefficient transport. In the Journal of the Royal Society Interface, researchers say they devised a mathematical model that predicts the sweet spot for sap: 23.5 percent sugar by weight.

That's far sweeter than Coke, which is 10 percent sugar. The researchers found sap sugar levels for 41 plants, which together average roughly 18 percent. The outliers include maize and potato (50 percent), suggesting that humans have domesticated plants that are on a natural sugar high.

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