GLACIAL PROFILING: The melting of North America's glaciers is speeding up, scientists with the U.S. Geological Survey announced Thursday. In its most exhaustive study yet of glacier shrinkage, the federal agency looked at three "benchmark" glaciers whose varying climates and elevations make them good indicators of glacial health across the continent. Washington state's South Cascade Glacier, the Wolverine Glacier on Alaska's Kenai Peninsula (pictured at right) and the Gulkana Glacier in interior Alaska have all undergone "rapid and sustained" retreat, the USGS reported, and it has accelerated in recent decades. "We've crossed a threshold," says one USGS scientist, "and these glaciers along with those globally are shrinking." (Source: Los Angeles Times, Guardian, McClatchy Newspapers)

 

CASH FOR CLUNKERS: The Senate approved $2 billion in additional funding Thursday night for the popular "cash for clunkers" rebate program, which doles out vouchers or dealership credits worth up to $4,500 for consumers who trade in gas guzzlers for more fuel-efficient cars. The 60-37 vote should help the program, which ran out of its original $1 billion allotment faster than expected, last until Labor Day. President Obama will likely sign the bill into law today. (Sources: Washington Post, CNN)

 

FISSION TO MARS: NASA is making some giant leaps toward developing trash-can-sized nuclear reactors that could one day generate power for lunar or Martian human outposts. If portable fission power is possible and practical off the planet — even just pumping out 40 kilowatts of usable energy — then colonizing the universe would be much easier. NASA's current plans involve getting astronauts back to the moon by 2020 to start laying the groundwork for a permanent outpost on the lunar surface, which in turn could set the stage for later manned missions to Mars. "The pace of progress exhibited by these three achievements in the same time period is exciting," a NASA official tells Space.com. "It has built the team's confidence and prepared them for challenges that lay ahead." (Source: Space.com)

 

NEW LEAF: The Toyota Prius could be toppled as the king of eco-cars by Nissan's Leaf, Nissan says. The No. 3 Japanese automaker has set its sights on No. 1 after years of letting Toyota and Honda dominate the hybrid market. But unlike the Prius, Insight and even the Chevy Volt, the Leaf is all-electric, meaning it uses no gasoline and can be refueled for less than $1, even with high electricity prices. Its limited range per charge (100 miles) may be more of a problem in the spread-out United States than in compact Japan, but Nissan is betting that paradigms have shifted enough that a market is opening up here. (Source: Agence France-Presse) 

 

CLEANUP ON ISLE TWO: After using the Puerto Rican island of Vieques for target practice since World War II, the U.S. Navy finally gave it a rest in 2003, and two years later the EPA declared the island a federal Superfund site. Under EPA rules, the Navy must clean up its own mess on Vieques, where residents believe long-term exposure to weapons-related toxins such as napalm, depleted uranium, mercury and lead has spurred disproportionately high rates of cancer and other illnesses. But since the island's dense forests are dotted with undetonated bombs, the Navy plans to simply burn down the vegetation, since sending people in there is too dangerous. For Vieques locals, it's just one more battle against the Navy they're unlikely to win. (Source: New York Times)

 

SAM AND KNUT: It was a sad day Thursday when Sam the koala, famously rescued from Australian bush fires by a firefighter in February, died during surgery aimed at saving her from life-threatening abdominal cysts. But there is at least some good news this week for another fur-covered international celebrity — Knut the polar bear, who became famous in 2007 when his mother rejected him shortly after he was born at a Berlin zoo, has a new girlfriend. Knut doesn't know it yet, but he'll soon be shacking up with 2-year-old Gianna, named after Italian rock singer Gianna Nannini. (Source: Huffington Post)

 

SOMETHING TO CROW ABOUT: One of Aesop's fables may be nonfiction. The story of the clever crow, who dropped rocks into a pitcher to raise the water level enough to drink, is something that a relative of crows, the rook, can actually do. Rooks and crows have already been shown to use tools ingeniously, even bending paper clips to suit their needs, but these rooks have raised the bar. They were presented with a clear plastic tube containing water, and a worm floating on the surface. They spontaneously used the fabled stone-dropping trick to raise the water level and eat the worm — they even appeared to estimate how many stones they'd need, and quickly figured out that bigger stones worked better than small ones. (Source: Associated Press)

 

— Russell McLendon