Tigers are "functionally extinct" in Cambodia, conservationists conceded for the first time on Wednesday, as they launched a bold action plan to reintroduce the big cats to the kingdom's forests.

Cambodia's dry forests used to be home to scores of Indochinese tigers but the WWF said intensive poaching of both tigers and their prey had devastated the numbers of the big cats.

The skimmer is lowered from the rear of the icebreaker, its weight pushing massive pieces of ice under the water and forcing the spilt oil up to the surface, where the sticky black goo can be sucked up.

Luckily, this is just a test: as the world's superpowers eye the lucrative Arctic region with growing interest, unprecedented oil spill clean-up tests in icy Finnish conditions reveal just how hazardous and challenging an accident in the Arctic's pristine sea ice could be.

The fate of humanity if aliens were to discover Earth with its balmy climate and bountiful resources, has long been a concern for scientists -- many of whom fear the worst.

Dozens of space scientists are desperately scouring the skies after losing track of a quarter-of-a-billion-dollar Japanese satellite that was sent to study black holes.

The ultra-high-tech "Hitomi" -- or eye -- satellite was supposed to be busy communicating from orbit by now, the Japan Aerospace Exploration Agency (JAXA) said, but no one can say exactly where it is.

After almost two years of coral bleaching, with some reefs bleaching twice and possibly three times since 2014, scientists have said that dire predictions of global coral decline made almost two decades ago may now be manifest.

The rolling underwater heatwave has now arrived upon the Great Barrier Reef, with mass die-offs expected along the northern quarter of the world’s preeminent coral ecosystem.

The hunters searching for mammoth tusks were drawn to the steep riverbank by a deposit of ancient bones. To their astonishment, they discovered an Ice Age puppy's snout peeking out from the permafrost.

Five years later, a pair of puppies perfectly preserved in Russia's far northeast region of Yakutia and dating back 12,460 years has mobilised scientists across the world. 

Fresh supplies shipped out late Tuesday for the International Space Station, where the shelves finally are getting full after a string of failed deliveries.

Launching beneath the light of a nearly full moon, the unmanned Atlas V rocket provided late-night sparkle as it headed north with its precious cargo and paralleled the East Coast on its way to orbit.

The United Nation's cultural body UNESCO has added 20 new sites to its network of protected biosphere nature reserves, including two in Canada and two in Portugal.

The status was conferred during a two-day meeting in Lima that ended Saturday, which brought the total number of biosphere reserves to 669 across 120 countries.

SeaWorld built its brand on a leaping and splashing killer whale named Shamu. She was part of its logo, gave her name to stadiums in the theme parks and was the inspiration for rides. The orca image sold T-shirts and soft, stuffed animals for the kids to take home.

With the company phasing out its killer whale program, it is forced to ponder the question: What is SeaWorld without Shamu?

Three new crew members have joined the International Space Station, including a U.S. grandfather who is poised to enter the record books during his time there, NASA said.

The Russian spacecraft carrying the astronauts docked at 0309 GMT Saturday some 407 kilometers (253 miles) above the Pacific Ocean, off the western coast of Peru, according to the American space agency.