After a four-week spring break, NASA’s Mars Curiosity rover has set its sights on the next drill target: Cumberland, a rock lying about 9 feet away from where the rover first broke ground in Yellowknife Bay.

The new target will be a greater challenge than the last, with more bumpy rock containing more erosion-resistant, mineral-rich concretions that formed when water once soaked the stone. 

Mission scientists wanted to play it safe for the first time the rover wielded its drill, said Ashwin Vasavada, a deputy project scientist on the Mars Science Laboratory at Jet Propulsion Laboratory...

Wondering where Earth’s climate is headed with an atmosphere that is 400 parts per million carbon dioxide?

An arctic bare of ice sheets, forested in pine and fir, with summer temperatures about 14 degrees Fahrenheit higher than today were typical some 3.5 million years ago, when atmospheric CO2 measures hovered around the 400 ppm range, according to researchers at the University of Massachusetts, Amherst.

The findings, based on sediment cores drilled from a Russian lake, don’t bode well for the current model of human-forced climate change, the researchers warn. They suggest that...

WASHINGTON -- The ratio of carbon dioxide in the Earth’s atmosphere has surpassed 400 parts per million in an average daily reading at Hawaii’s Mauna Loa Observatory, the highest concentration of the heat-trapping greenhouse gas in millions of years.

While several atmospheric readings in the Arctic have recently exceeded 400 ppm of carbon dioxide, the Mauna Loa daily average readings are considered the benchmark indicators of the Earth’s atmospheric makeup.

Climate scientists have calculated that the world needs to keep carbon dioxide emissions from crossing the 400-ppm...

The sun is ramping up toward solar maximum -- the white-hot peak of activity in an 11-year cycle -- and NASA has been snapping images of the phenomenon every 12 seconds for three years.

The space agency put together a three-minute video showing images taken by the Solar Dynamic Observatory since spring 2010. As the Los Angeles Times' Deborah Netburn reported last month, the NASA video stitches together two SDO images per day over the three-year period.

Alex Young, a heliophysicist at Goddard Space Flight Center, narrates the video to point up some of the sun's best-of momentsin that time...

Astronauts from the International Space Station will start their space walk Saturday about 5:45 a.m. Pacific time, in an effort to locate and fix an ammonia leak in a coolant system, NASA officials said Friday.

The unscheduled emergency walk was "precedent setting" for the station, although similar impromptu tasks had been performed during the Space Shuttle program, said Norm Knight, NASA chief flight director.

“The team is ready to go,” International Space Station program manager Michael Suffredini said.

“Things are really progressing in the right direction,” added...

Some say that you can’t put a price on precious natural resources. As of this week, you can.

The public and private tab for conserving the nation’s fish, wildlife and natural resources is close to $40 billion a year, according to a study released this week.

The analysis, commissioned by the National Fish and Wildlife Foundation, considered the jobs, tax revenue and other economic effects from federal state and private investment in conservation.

The total -- $38.8 billion — stimulates as much as $93.2 billion in economic activity, the study found.

A coalition of more than 1,...

In yet another scathing critique of government health officials, a federal judge refused Friday to stay his order making Plan B emergency contraceptives available to all consumers without a prescription.

Ruling that government efforts to restrict the drug's sale were "frivolous and taken for the purpose of delay," U.S. District Judge Edward R. Korman of New York wrote that the drug would be available to all unless the 2nd Circuit Court of Appeals ruled otherwise by noon on Monday.

The action was just the latest in a long battle between reproductive rights advocates and two White House...

Two federal agencies on Friday announced a major review of how seismic testing for oil and gas deposits affects marine mammals and fish in deep waters off the Gulf of Mexico.

So-called seismic surveys entail blasts from air guns or other ship-borne devices that send out powerful sound waves that reflect the shape and extent of oil and gas fields under the ocean floor. Industry officials say the practice is necessary for efficient, safe exploration in deep seas.

The testing has long been controversial. Environmental groups have taken companies connected to the tests to court many times, ...

Astronauts on the International Space Station may take a spacewalk Saturday to repair an ammonia leak.

The gas, used to cool one of the station’s solar arrays, began oozing from the left side of the station’s truss structure Thursday, officials said.

NASA reported that the six-member Expedition 35 crew, commanded by Chris Hadfield, was not in danger, and that the station is operating normally while crew members and mission managers work to reroute power through another of the station’s eight power channels.

"The whole team is ticking like clockwork, readying for tomorrow. I...

Swing, batter, batter! In less time than it takes to say that phrase, Major League Baseball sluggers have their bat across the plate, and the best of them are golfing the shot over the outfield wall.

How does the brain "know" when to swing? Researchers at UC Berkeley believe they've found the internal architecture that lets a batter get ahead of the fastball, and allows the rest of us to pour a beer and find our seat in the stands. They pinpointed a region of the brain's middle temporal complex that can "predict" spatial position ahead of its actual location in the real world.

For example, in...

Less than a week after the Food and Drug Administration announced that it would investigate the safety of added caffeine in U.S. food and beverage products, Wrigley North America has decided to put its bid to market a caffeinated gum on hold out of respect for the agency's deliberations, the company's president, Casey Keller announced in a statement issued to the Associated Press.

The move appears to be a bow to FDA Deputy Commissioner Michael R. Taylor's public suggestion last week that "together, we should immediately be looking at what voluntary restraint can be used by industry as FDA gets...