Most of the radioactive fallout from the disaster at the Fukushima nuclear plant dropped into the ocean and began circling the planet, Japanese researchers said Thursday.

Up to 80 percent of the cesium released by the Fukushima Daiichi power plant landed in the Pacific and made its way into other oceans around the world, scientists at the Meteorological Research Institute said.

For more than half a century, geologists have wrangled over the origins of an astonishing range of mountains found beneath ice up to three kilometers (two miles) thick in East Antarctica.

Named after the Soviet geophysicist who detected them in 1958 during the first International Polar Year exploration, the Gamburtsev mountains are 1,200 kilometers (750 miles) long, with jagged peaks up to 2,700 meters (8,900 feet) high intersected by deep troughs and valleys.

France's nuclear watchdog on Tuesday said it had detected traces of radioactive iodine in the air last week after similarly low contamination was reported by the Czech Republic, Poland, Slovakia and Austria.

Concentrations of iodine 131 measuring a few microbecquerels per cubic meter were detected last week at four monitoring stations in northern and eastern France, the Institute for Radiological Protection and Nuclear Safety (IRSN) said.

Scientists are beginning to decode the complex biology of aging and are optimistic that recent advances in research may lead to treatments that can slow or even reverse degeneration and disease.

"We are seeing a major change, very important developments and real therapeutic efforts to try to treat age-related illnesses," said Norman Sharpless, professor of medicine and genetics at the University of North Carolina.

Rescuers were racing against the clock Monday to save two huge sperm whales stranded on a Tasmanian sandbank after 22 others died, the Parks and Wildlife Service said.

Marine mammal specialists were on site in Macquarie Harbor at Strahan on Tasmania's northwest coast, but the rescue bid was hampered by rough weather.

Russia on Monday successfully launched three astronauts for the International Space Station, boosting morale after accidents raised doubt about the reliability of its space program.

The launch of two Russians and an American on a Soyuz-FG rocket had been delayed for almost two months after a unmanned Russian Progress supply ship in August crashed into Siberia shortly after its launch on a similar rocket.

Russia made desperate efforts on Thursday to re-establish contact with a pioneering Mars probe that now hangs in a low Earth orbit and could potentially crash back down in a matter of days.

The unmanned Phobos-Grunt spacecraft failed to find the right course to the Red Planet and its moon Phobos after taking off from a space centre Russia leases in Kazakhstan early Wednesday.

Six men who spent 520 days in isolation in Moscow to simulate a flight to Mars on Tuesday spoke of their pride at becoming "spacemen" but complained of the monotony and cravings for crusty baguettes.

Wearing blue jumpsuits and badges with the project name Mars 500, the international team of one Chinese, one Italian, one Frenchman and three Russians said they were proud of their "flight" in a Moscow car park.

An asteroid bigger than an aircraft carrier will dart between the Earth and moon on Tuesday — the closest encounter by such a huge rock in 35 years.

But scientists say not to worry. It won't hit.

Harmful carbon emissions from burning fossil fuels made their biggest ever annual jump in 2010, according to the U.S. Department of Energy's latest world data released this week.

China led the way with a spike of 212 million metric tons of carbon in 2010 over 2009, compared to 59 million metric tons more from the United States and 48 million metric tons more from India in the same period.