An African elephant in Vienna Zoo has been impregnated using frozen sperm from a male living in the wild, in what the Zoo said Monday was a world first.

Pregnancy has been achieved before elsewhere using frozen sperm in two cases, once with an African elephant and once with an Asian one, but both times the males were in captivity and the fetuses died, a zoo spokeswoman told Agence France Presse.

U.S. President Barack Obama on Monday ribbed scientists behind NASA's roving robot Curiosity, instructing them to let him know right away if they found life on Mars.

"If in fact, you do make contact with Martians, please let me know right away," Obama joked, as he called the scientists at NASA's Jet Propulsion Laboratory in California from Air Force One.

Bats in the bleachers of Olympic Stadium? Now there's an Olympic legacy to give many people nightmares.

But not Kim Olliver. Faced with the prospect of having bats take up residence in the girders of Olympic stadium, Olliver, the senior ecologist for the London Olympics, could barely contain her joy.

The U.N. chief Sunday announced an initiative to protect oceans from pollution and over-fishing and to combat rising sea levels which threaten hundreds of millions of people.

United Nations Secretary General Ban Ki-moon said the initiative, called the Oceans Compact, sets out a strategic vision for the U.N. system to work more effectively to tackle the "precarious state" of the world's seas.

A mass of small volcanic rocks nearly the size of Belgium has been discovered floating off the coast of New Zealand.

The stretch of golf-ball-size pumice rocks was first spotted this week by a New Zealand air force plane about 1,000 kilometers (620 miles) northeast of Auckland. The rocks stretch for about 26,000 square kilometers (10,000 square miles).

A conservationist says seven of the world's rarest rhinoceroses were photographed at a national park in Indonesia. It is the first sighting there in 26 years.

Tarmizi, from the Leuser International Foundation, said Thursday that pictures from movement-triggered cameras identified a male and six female Sumatran rhinos in Aceh province's Leuser National Park as of April.

Earlier this week NASA safely landed a robotic rover on Mars about 150 million miles (241.39 million kilometers) away. But on Thursday here on Earth, a test model planetary lander crashed and burned at Kennedy Space Center in Florida just seconds after liftoff.

The spider-like spacecraft called Morpheus was on a test flight at Cape Canaveral when it tilted, crashed to the ground and erupted in flames. It got only a few feet up in the air, NASA said.

Scientists in Switzerland said on Friday they had devised software that can swiftly trace terror suspects, computer viruses, rumor-mongering and even infectious diseases back to their source.

"Using our method, we can find the source of all kinds of things circulating in a network just by 'listening' to a limited number of members of that network," said researcher Pedro Pinto of Lausanne's Federal Polytechnic (EPFL).

The U.S. space shuttle Endeavour will arrive in Los Angeles next month before making its way across the city in October to its new home at the California Science Center, officials said Wednesday.

Endeavour, which completed its last mission a year ago, will be flown on the back of a modified Boeing 747 from Florida's Kennedy Space Center to Los Angeles on September 20, where it will remain for a few weeks in a hangar.

Threatened shark species are being used to make shark fin soup, a delicacy in Chinese cuisine, in several U.S. cities, according to an unprecedented study based on DNA testing.

Thirty-three different species of sharks turned up in samples collected in 14 cities and analyzed at Stony Brook University's Institute for Ocean Conservation Science in New York.