FREIGHT WATCHERS 

For the first time ever, the U.S. unveiled fuel-efficiency standards for heavy-duty vehicles Tuesday, mimicking an effort that has already been slowly boosting the mileage of light-duty cars since 1975. The new rules cover tractor-trailers, garbage trucks and other automotive hulks that often get no more than 6 miles per gallon, calling for 9 to 23 percent reductions of fuel consumption and greenhouse-gas emissions by 2018, depending on the type of vehicle.

Heavy-duty vehicles make up just 4 percent of all domestic automobiles in the U.S., the Los Angeles Times reports, but due to their long trips, frequent idling and low fuel efficiency, they consume about 20 percent of all vehicle fuel. The new efficiency standards could raise heavy-duty fuel economy from an average of 6 mpg to 8 mpg, which is a bigger deal than it sounds like, one expert tells the New York Times. "A typical long-haul truck, running 150,000 miles a year at 6 miles a gallon, is burning 25,000 gallons a year," says Allen Schaeffer, executive director of a diesel-technology trade group. At a price of $4 a gallon, that means $100,000 in annual fuel costs, he notes. The rules will initially cost buyers $8 billion, according to EPA estimates, but will end up paying for themselves in a year or two thanks to fuel savings. Throw in other perks like reduced refueling time and lower greenhouse-gas emissions, and the rules' total benefits will exceed costs by $49 billion over a vehicle's lifetime, according to the EPA.

President Obama announced the rules at a time when Congress has shown little appetite for new environmental regulations, so he was quick to point out not only the fuel savings, but also the fact that manufacturers and owners of heavy-duty trucks had requested efficiency standards. "While we were working to improve the efficiency of cars and light-duty trucks, something interesting happened," Obama said in a statement. "We started getting letters asking that we do the same for medium and heavy-duty trucks. They were from people who build, buy and drive these trucks." The trucking industry has been far more receptive to such rules than many car makers have been, the New York Times reports, apparently subscribing to the idea that a rising tide lifts all trucks.

(Sources: New York Times, Los Angeles Times)

SOLAR EXPRESS 

For all the benefits of electric cars, they do have one glaring environmental downside: Although they replace oil with electricity, most of that electricity is generated using coal, which is even dirtier than oil. That's the impetus behind a new add-on for Ford's upcoming 2012 Focus electric sedan: a solar energy system that will let Focus owners power their cars with homemade, emissions-free electricity. Ford is working with solar provider SunPower on the project, which includes a package of rooftop panels along with the Focus, USA Today reports.

"In effect, you are driving a solar-powered car," says SunPower CEO Tom Werner, adding that customers have often commented, "'Wouldn't it be cool if I could power my car?'" The rooftop panels won't necessarily charge the car's batteries directly, USA Today points out, since they're just like any other solar panels, providing electricity to the entire house. But to make sure the Focus is "in effect" a solar-powered car, the solar add-on will generate enough electricity to offset about 1,000 miles of driving per month. To reach that 1,000-mile benchmark, the SunPower system will need to cover roughly 147 square feet, which is divided into 11 panels measuring 4 feet by 2 feet. In one year, the 2.5-kilowatt system is expected to generate about 3,000 kilowatt hours of electricity, USA Today reports.

It won't be cheap, though: The solar package will cost about $10,000 after federal tax credits (Ford hasn't yet revealed the price of its 2012 Focus EV). But Best Buy's Geek Squad has signed on as an official installer of the solar panels, and the lure of a car fueled by sunlight — however indirectly — could bring a new demographic into the solar marketplace, argues Ron Cogan, publisher of the Green Car Journal. "It's pretty brilliant marketing," Cogan tells USA Today. In addition to expanding the overall appeal of electric cars, "it's going to introduce a whole new crowd of people to solar power who might not have gone there otherwise."

(Source: USA Today)

MIGHTY MICE 

Viruses and bacteria have a track record of evolving into "superbugs," which can survive drugs designed to kill or control them. But according to a new study in Current Biology, some house mice in Europe are now doing the same thing. In a "highly unusual" development for a mammal, mice in Germany and Spain have rapidly evolved a resistance to even the strongest rodent poisons, potentially making them immune to almost any kind of pest control.

Mice around the world have been slowly developing a partial resistance to warfarin — an anticoagulant that's the most common form of mouse and rat poison — as well as other chemicals, but mainly just in isolated pockets, the BBC reports. Yet when some German and Spanish mice recently began breeding with a different species of mouse from Algeria — a species that had been evolving separately for more than 1 million years — their offspring showed an ability to resist virtually every poison that's used against mice. Most of these offspring are infertile, which is common when two different species mate, but a few of them are able to reproduce, the researchers say. "Our study is so special because it involves hybridization between two species of mouse that are 1.5 to 3 million years removed from each other," lead author Michael Kohn tells the BBC. "Most of the offspring ... do not reproduce; they are sterile. But there is a small window, which remains open for genes to be moved from one species to the other, and that's through a few fertile females — so there is a chance to leak genes from one species to another."

These few fertile females have already helped spread the resistance gene throughout "the vast majority of mice in Spain," according to the BBC, as well as "a growing number in Germany." And according to Kohn, as global travel and shipping continues to spread mice around the world, more of these hybrid supermice could begin showing up — despite the evolutionary hurdles involved when two species try to become one. "There are a lot of genetic barriers between these species of mice," he says. "To see them hybridize and transfer genetic material is quite spectacular, to be frank."

(Source: BBC News)

STAR POWER 

The sun erupted Tuesday with the most powerful type of solar storm, an X-class flare that was rated X6.9. And as Space.com reports, this type of violent solar flare will only become more common over the next two years, as the sun approaches its maximum level of activity in 2013. Humans were lucky that Tuesday's flare wasn't pointed directly at the Earth, which meant most of its charged particles soared harmlessly into space. But if scientists' forecasts are correct, it could just be a taste of things to come.

"We still are on the upswing with this recent burst of activity," says Phil Chamberlin, a solar scientist at NASA's Goddard Space Flight Center and a deputy project scientist for the agency's Solar Dynamics Observatory. "We could definitely in the next year or two see more events like this; there's a potential to see larger events as well." The sun goes through 11-year cycles of magnetic activity, and it's now coming out of a lull — the current solar cycle began in 2008, and is expected to reach its peak in 2013. Solar flares are relevant here on Earth because the charged particles they release can wreak havoc with satellites, power grids, telecommunications systems and other infrastructure, and can also pose a risk to astronauts in orbit.

The U.S. Space Weather Prediction Center issues warnings when it detects that a solar flare has occurred, but scientists still struggle to predict the storms before they strike. Satellite and power companies are working to develop infrastructure that can withstand solar bombardment, but for now, there's little anyone can do but wait for the sun's next move. "We're being reactive, we're not being proactive," Chamberlin says. "We don't know how to predict these things, which would be nice."

(Sources: Space.com, Space Weather Prediction Center)

THIS DAY IN HISTORY

A virus kills 20 percent of harbor seals, one of the WWFs is forced to change its name, and more.

Russell McLendon

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Photo (big rigs at night): U.S. National Energy Technology Laboratory

Photo (Ford electric cars at the 2011 Detroit auto show): ZUMA Press

Photo (three house mice on a burlap sack): ZUMA Press

Photo (X-class solar flare): NASA

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