Italian holidaymakers had more than just a lazy day in the sun Wednesday after a rare visit from a blue shark that came to wallow just 10 meters from a beach outside Rome, said local coastguard.

Swimmers were ordered out of the water as a precaution though the 1.5-meter long shark -- tempted inshore to bathe in hotter-than-usual water temperatures in the Mediterranean as southern Europe swelters under a heatwave -- was thought to be harmless.

An ice core extracted from an Antarctic islet has yielded further evidence of the impact of man-made warming on the frozen continent, fuelling concern for the future of ice shelves, a report said Wednesday.

The 364-meter ice core drilled from James Ross Island on the Antarctic peninsula has been studied in laboratories in Europe for the past four years, for its 15,000-year record of snowfalls holds clues about climate shift.

Taiwanese researchers said Thursday they have developed a strain of rice that cooks particularly soft for elderly people to meet the needs of a rapidly greying society.

The new strain was developed by the Miaoli District Agricultural Research And Extension Station in central Taiwan after a decade-long process and was expected to hit the market next year, they said.

A little more than two weeks after its arrival on Mars, NASA's Curiosity rover will on Wednesday make its first "test drive" before setting off on its Red Planet mission, the U.S. space agency said.

The $2.5 billion rover, which landed on Mars on August 6, has performed a battery of tests and appears ready to embark on its two-year mission to explore the Red Planet in the hunt for signs of life, NASA said Tuesday.

The Arctic ice cap is melting at a startlingly rapid rate and may shrink to its smallest-ever level within weeks as the planet's temperatures rise, U.S. scientists said Tuesday.

Researchers at the University of Colorado at Boulder said that the summer ice in the Arctic was already nearing its lowest level recorded, even though the summer melt season is not yet over.

Fossils of toothy, slug-like creatures that grazed the sea floor 500 million years ago have shed light on the origins of modern-day snails, shellfish and squid, a study said Wednesday.

The most comprehensive analysis yet of the ancient slugs' mouth parts -- multiple rows of teeth that moved in conveyor-belt fashion, showed they were related to present day molluscs, scientists wrote in the journal Proceedings of the Royal Society B.

Heatwaves, drought and floods that have struck the northern hemisphere for the third summer running are narrowing doubts that man-made warming is disrupting Earth's climate system, say some scientists.

Climate experts as a group are reluctant to ascribe a single extreme event or season to global warming.

Giving babies antibiotics before the age of six months could cause them to be chubby children, according to a study published Tuesday.

"We typically consider obesity an epidemic grounded in unhealthy diet and exercise, yet increasingly studies suggest it's more complicated," said co-author Leonardo Trasande of the New York University School of Medicine.

Global wildlife monitoring network TRAFFIC warned Tuesday that 515 rhinos could perish by the end of the year if no action is taken to stem the illicit trade in rhino horns.

In its latest report, the agency said that with a total of 281 animals killed as of July, there was a "predicted loss of 515 by year end if current poaching rates continue".

An ancient skull discovered in a cave in Laos has pushed back the clock on human migration to Southeast Asia by as much as 20,000 years, a study published Monday has found.

The skull discovered in the Annamite Mountains in northern Laos is the oldest modern human fossil found in Southeast Asia and is believed to be between 46,000 and 63,000 years old.