Warmer-than-normal ocean temperatures around Hawaii this year will likely lead to the worst coral bleaching the islands have ever seen, scientists said Friday.

Many corals are only just recovering from last year's bleaching, which occurs when warm waters prompt coral to expel the algae they rely on for food, said Ruth Gates, the director of the Hawaii Institute of Marine Biology. The phenomenon is called bleaching because coral lose their color when they push out algae.

A Russian space capsule landed safely in Kazakhstan on Saturday, bringing home a three-person crew from the International Space Station, including a record-breaking Russian cosmonaut.

Russia's Gennady Padalka, Andreas Mogensen of the European Space Agency and Aidyn Aimbetov of Kazakhstan landed on the steppe just two minutes before sunrise and were feeling fine. Their Soyuz TMA-16M capsule touched down on schedule at 0651 local time (0051 GMT) Saturday, 146 kilometers (90 miles) southeast of Dzhezkazgan, in what a NASA commentator called a "bull's-eye landing."

Japanese fishermen on Friday killed the first dolphins of the season in a controversial annual hunt that attracted global attention after it was featured in the Oscar-winning 2009 documentary "The Cove".

An official with the local fishing union in the small town of Taiji said boats left early Friday morning and trapped a dozen dolphins.

Europe sent two satellites into space Friday as it pushes to get its beleaguered Galileo satnav program back on track.

Orbiters nine and 10 were launched from Europe's spaceport in Kourou, French Guyana, at 0208 GMT -- bringing the satellite navigation system a third of the way to full deployment.

The fossilized bones of 15 bodies from a previously unknown human species have been discovered in a cave in South Africa, it was announced Thursday, in what scientists hailed as a breakthrough in evolution research.

About 1,500 fossils were found deep in a cave system outside Johannesburg, hidden in an underground chamber only accessible via several steep climbs and rock crevasses.

China is planning to land a lunar probe on the far side of the moon, state media reported, the latest step for Beijing's ambitious space programme.

The mission will be launched before 2020 and aims to land a probe on a part of the moon never visible from earth, the official Xinhua news agency reported, citing officials at the Chinese Academy of Sciences.

Europe is poised for the launch on Friday of the next two satellites in its troubled multi-billion-euro Galileo satnav programme.

The project -- a rival to America's GPS for navigation and search-and-rescue services -- will ultimately consist of a constellation of 30 orbiters, including six spares, but it has been plagued by delays, technical glitches and budget questions.

Australian scientists have discovered what could be a new species of the deadly funnel-web spider, after finding a large specimen living in a national park.

The 50-millimetre (two-inch) spider found in Booderee National Park near Jervis Bay south of Sydney is believed to be from the Hadronyche genus, which typically lives in trees.

Sperm whales create social cliques based on a shared dialect of vocal clicks, evidence that humans are not alone in having culture, according to research published Tuesday.

Combining data gleaned from decades of field observation and computer models, the study suggests social learning, rather that genetic transmission, explains how these giant sea mammals cohere into distinct "clans".

European experts have pulled off a major advance that might one day help build new worlds in space after an astronaut in the International Station Station remotely guided a robot on Earth by feel.

Danish astronaut Andreas Mogensen performed the breath-taking experiment in which he placed a peg into a very tight hole on Monday under the careful control of the European Space Agency.