North Korean leader Kim Jong-Un has opened a science and technology complex in Pyongyang, the North's state media said Saturday, adding another ostentatious building to the impoverished country's showcase capital.

His attendance at the ceremony on Friday marked his first public appearance since his New Year address, when he vowed to raise living standards in the struggling one-party Stalinist state.

A swimmer Saturday suffered wounds to his arms and legs after he was mauled in a suspected shark attack off Queensland state on Australia's east coast, officials said.

The latest reported attack comes during the busy summer season, and as authorities in neighboring New South Wales implement a range of shark-prevention measures to reduce encounters after a spate of maulings in the state last year.

Researchers have succeeded for the first time in reversing a degenerative illness in mice, using a revolutionary gene-editing technique that one day may help cure similar diseases in humans.

Three studies published Thursday in the journal Science said researchers employed a technique known as CRISPR -- clustered regularly interspaced short palindromic repeats -- to cure an adult mouse model suffering Duchenne muscular dystrophy, a disorder that affects one in every 5,000 baby boys.

A giant squid that wandered into a Japanese port has been guided back out to sea almost a week after it was spotted, giving enthusiasts and experts a rare glimpse of the mysterious creature.

The massive invertebrate, four metres (13 feet) in length, was discovered by fishermen on December 24 at a port in the city of Toyama on Japan's northwestern coast.

A pair of Chilean condors have been brought to a zoo in Medellin as part of an effort to reintroduce the majestic birds in Colombia, where they have become all but extinct.

"Condors are a very endangered species," said Sandra Correa, director the Santa Fe Zoo in Medellin, who said the goal is to mate the birds to help replenish the population in Colombia, where only about 100 condors remain.

Planet Earth could be at higher risk of a space rock impact than widely thought, according to astronomers who suggested Tuesday keeping a closer eye on distant giant comets.

Most studies of potential Earth-smashers focus on objects in the asteroid belt roughly between Mars, Earth's outside neighbor, and Jupiter on its other flank, said the researchers.

SpaceX successfully landed its powerful Falcon 9 rocket in an upright position on Monday, a historic first in the company's bid to make rockets as reusable as airplanes.

"The Falcon has landed," a commentator said above the screams and cheers of people gathered at SpaceX headquarters in Hawthorne, California.

Australian scientists Tuesday hailed the discovery of two sea snake species feared to have become extinct years ago off the Western Australia coast.

The short-nose sea snake and the leaf-scaled sea snake had not been seen since disappearing from their only known habitat on Ashmore Reef in the Timor Sea more than 15 years ago, James Cook University researchers wrote in the Biological Conservation journal.

Two American astronauts will step out on a short spacewalk Monday to move a stalled rail car that is stuck outside the International Space Station, NASA said.

Commander Scott Kelly and Flight Engineer Tim Kopra will float out of the orbiting lab to move the mobile transporter rail car "a few inches," NASA said in a statement on Sunday.

SpaceX on Sunday counted down to its first rocket launch since an explosion after liftoff destroyed its unmanned Dragon cargo ship bound for the International Space Station six months ago.

The Falcon 9 rocket is poised to launch at 8:29 pm (0129 GMT Monday) from Cape Canaveral, Florida, announced the California-based company headed by Internet tycoon Elon Musk.