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Humpback whales swim in amazingly straight lines during their seasonal migrations that cross thousands of miles of open ocean, and a new study says it's not clear how they're able to chart such a steady course.

"It's just absolutely remarkable how straight these courses are," says Travis Horton, an environmental scientist at the University of Canterbury in New Zealand, who studies animal migrations. "They're doing something rather precise. They're actively and deliberately navigating within some sort of external reference frame."

Terry Button is a fifth-generation farmer from upstate New York who also works as a long-distance trucker, hauling hay and produce up and down the East Coast.

He's proud of his truck and likes it just the way it is. Inside, the cab is homey and low-tech, with a bed behind the two seats and a CB radio. There's no cruise control and no GPS telling him where to go.

The private rocket company SpaceX says its next rocket will be the most powerful in the world.

The new rocket, called the Falcon Heavy, is designed to carry up to about twice as much weight as a NASA space shuttle can take to orbit. It's expected to be at the launchpad at the end of next year for its first flight, with the launch likely coming in 2013.

SpaceX CEO Elon Musk described his company's new rocket during a press conference in Washington, D.C. He says it will be able to take about 117,000 pounds to orbit.

Little is known about the state of Japan's nuclear power plants, several of which sustained heavy damage in last Friday's earthquake. Officials think a partial meltdown may have occurred at the Fukushima Daiichi power plant.

Space shuttle Discovery glided down to Earth for the very last time Wednesday.

Crowds gathered to watch the beloved workhorse of NASA's shuttle fleet roll to a stop on the runway at Kennedy Space Center in Florida.

"And Houston, Discovery for the final time, wheel stop," Commander Steve Lindsey reported to Mission Control.

He thanked NASA workers for giving his crew "a perfect vehicle from start to finish on her final flight."