A review of more than 900 marine mammals hunted, stranded or captured for research along Alaska's coast has found toxins from harmful algae in 13 species, creating concern that the natural poisonous substances could increase as water warms and sea ice diminishes.

Algal toxins were present in animals sampled from southeast Alaska to the Arctic Ocean. Researchers from the National Oceanic and Atmospheric Administration and other agencies examined feces, stomach content and urine for two toxins.

Algal toxin has led to deaths of sea lions documented since 1998 in central California. They have been found previously in Alaska, at times creating health concerns for people eating clams, but have not been documented to this extent, said Kathi Lefebvre, a research biologist for the NOAA.

Earth loses touch with comet probe

European scientists said that they have stopped sending commands to the Philae space probe, which became the first to touch down on a comet more than a year ago.

The German Aerospace Center, or DLR, said it last made contact with the lander July 9, but efforts since then have failed. Conditions on comet 67P/Churyumov-Gerasimenko have become so cold — falling below minus 180 degrees Celsius at night — that the washing-machine-sized probe couldn't function.

"It would be very surprising if we received a signal now," said Philae project manager Stephan Ulamec.

The comet is 138 million miles from Earth, between the orbits of Mars and Jupiter.

NASA gets a hand on roommates

When NASA selects astronauts to travel to Mars sometime after 2030, they will need a small crop of candidates who are smart, skilled — and personable.

For a voyage almost 34 million miles one way, the astronauts will need to work well together in an isolated and uncomfortably tight environment, as well as cope with boredom and the continuous company of the same tiny group of people.

Researchers at Johns Hopkins University recently won a NASA grant to help the agency develop a method of sorting elite candidates.

"NASA is already really good at picking people," said Michael Rosen, a Hopkins psychologist who is leading the effort. "But they'll need to be better."

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