The operator of the crippled Fukushima nuclear plant said Tuesday workers had spilled four tonnes of radioactive water, likely contaminating the soil and possibly groundwater.

Workers were pumping rain water that was trapped in a concrete gutter into an empty 12-tonne tank that sat on open soil, said a spokesman for Tokyo Electric Power (TEPCO).

Researchers said on Tuesday they had created saliva glands and tear glands using stem cells from mice, marking a further advance in the quest to grow replacement bio-engineered organs.

The work shows potential for treatments for malfunctioning glands that cause "dry eye" or "dry mouth" syndromes, which affect tens of millions of people around the world, they said.

Arctic ice melt due to global warming is having an unexpected impact on West Greenland's caribou, causing fewer calves to be born and boosting their death rate, a study said Tuesday.

Accelerated ice melt has caused the plant growth season on Greenland to start ever earlier -- about 16 days sooner on average in 2011 than in 2002, scientists wrote in the journal Nature Communications.

You expect to find plastics in your lunch box, not on a moon of Saturn.

But that's exactly where NASA found an ingredient of plastic — the first time the chemical has been detected on another world.

Oral arguments are scheduled to begin Dec. 13 for a legal case challenging Hawaii's decision to grant a permit for the construction of the world's largest optical telescope at the summit of Mauna Kea.

Opponents of the Thirty Meter Telescope appealed a Board of Land and Natural Resources decision to the Third Circuit Court in Hilo in May.

Citrus production in Florida, the world's second largest orange juice supplier after Brazil, is being threatened by a bacteria from Asia that has scientists racing for a remedy.

Known as citrus greening, the disease makes oranges bitter and fall from the tree before they can ripen.

New Zealand authorities said Tuesday that eight endangered kiwi birds have died from respiratory infections while being treated at Wellington Zoo, in a loss described as "a tragedy" for conservation efforts.

The eight birds were all juvenile rowi kiwi, the rarest sub-species of New Zealand's emblematic flightless birds, the Department of Conservation (DOC) said.

NASA is preparing to launch a 3-D printer into space next year, a toaster-sized game changer that greatly reduces the need for astronauts to load up with every tool, spare part or supply they might ever need.

The printers would serve as a flying factory of infinite designs, creating objects by extruding layer upon layer of plastic from long strands coiled around large spools. Doctors use them to make replacement joints and artists use them to build exquisite jewelry.

Russia on Monday successfully launched a Proton-M rocket with a European communication satellite on board, marking a return of its most important unmanned space vehicle three months after one exploded on takeoff.

The launch from the Baikonur space center that Russia leases from the neighboring Central Asian nation of Kazakhstan had been originally scheduled for July 21.

Researchers in Sweden said Friday they had developed a new medicine to protect bees from diseases that kill entire populations of the insect in the U.S. and Europe.

A team of microbiologists at Lund University have patented the treatment, known as SymBeeotic -- made from lactic acid bacteria from the stomachs of healthy bees -- which they described as a major "boost" to bees' immune system and are hopeful that it could slow down the rate at which bees are dying.