Scientists think they have solved the mystery of what's killing starfish along the U.S. Pacific coast. It's a virus.

The Senate's vote next week on legislation to force approval of the Keystone XL pipeline may come down to a handful of Democrats, who are now being courted aggressively by advocates on both sides of the debate."

"The controversial government program that funded failed solar company Solyndra, and became a lighting rod in the 2012 presidential election, is officially in the black."

"Halliburton Co. is in talks to buy Baker Hughes Inc. in a deal that would combine two of the largest and oldest names in the energy business as plunging oil prices send the industry into a downturn."

"ANCHORAGE -- Six environmental groups sued Monday to throw out a federal agency rule that concludes oil exploration off Alaska’s northwest coast has a negligible effect on walrus."

"The U.S. State Department must halt plans to expand an oil sands pipeline route from Canada to Wisconsin until possible environmental harm has been closely studied, several green groups said in a lawsuit filed on Wednesday."

"Legislation to force the approval of the Keystone XL pipeline picked up support Thursday as more Democratic senators signed on to Sen. Mary Landrieu's effort."

"Don Blankenship, the longtime chief executive officer of Massey Energy, was indicted Thursday on charges that he orchestrated the routine violation of key federal mine safety rules at the company’s Upper Big Branch Mine prior to an April 2010 explosion that killed 29 miners."

"Health concerns about oil field fracking have been focused on the mixed brew of chemicals injected into wells. But it is another innocuous-sounding substance — sand — that poses a more serious danger to workers."

"U.S. wildlife authorities listed the Gunnison sage grouse as threatened on Wednesday, disappointing environmental activists who wanted the species given greater protection, and politicians who did not want the federal government involved."