In half a century of space travel more than 500 people have glimpsed the Earth from the unique vantage point of the cosmos, yet no black African has been among them.

Now a Nigerian and two South Africans are in a race to become the first after being shortlisted in a global talent search to send a "young icon of the future" into the heavens.

Under attack from hordes of ravenous starfish, Pacific coral is getting help from an unexpected source -- seaweed, an arch enemy, researchers said on Wednesday. 

Seaweed is no friend of the fragile ecosystems of coral reefs, pumping out harmful chemicals, blocking out life-giving sunlight, and rubbing up against and damaging the threatened marine invertebrates.

Deep in the pristine Amazon jungle, Brazil's newest skyscraper has a mission unlike any other: to save the world.

The white and orange metal frame called Amazon Tall Tower Observatory, or ATTO, is a bold new tool in the push to understand climate change and the vital role of rainforests.

Thailand destroyed more than two tonnes of ivory Wednesday -- a victory for animal rights groups fighting against the trade in a country renowned for being a hub for illegal tusks.

The ceremony, in which 2,155 kilograms of raw tusks and carved trinkets were fed into an industrial rock crusher before being incinerated, was presided over by the Thai junta leader Prayut Chan-O-Cha and is the first time the kingdom has taken steps to destroy part of its stockpile. 

Australia's city of Newcastle, which claims to be the world's biggest coal export port, said Wednesday it will pull money out of fossil fuel industries and invest in more sustainable enterprises.

Newcastle City Council, which manages a Aus$268 million (U.S.$191 million) investment fund for Australia's seventh largest city, voted late Tuesday to move progressively towards "environmentally and socially responsible investments".

U.S. President Barack Obama made a full-throated defense of renewable energy Monday, hitting coal-championing critics as free market hypocrites. 

With one eye on a looming battle over power plant emissions limits, Obama took on fossil fuel supporters during a speech in the parched desert oasis of Las Vegas.

High above the crowded streets of Addis Ababa, among fields where farmers lead oxen dragging wooden ploughs, sits Ethiopia's space program.

Perched on the top of the 3,200-meter (10,500-foot) high Mount Entoto, two metal domes house telescopes, each a meter in diameter.

Australian scientists revealed Tuesday they are using micro-sensors attached to honey bees as part of a global push to understand the key factors driving a worldwide population decline of the pollinators.

There has been a sharp plunge in the population of honey bees, which pollinate about 70 percent of global crops, or one-third of food that humans eat including fruits and vegetables, raising fears over food security.

Twin cubs born to a rare giant panda called Mei Xiang were doing well Sunday, vocal and "very, very active" after the surprise back-to-back births at the Smithsonian National Zoo, her handlers said.

The cubs were successfully swapped out early Sunday after being closely monitored through the night by experts concerned about their mother's ability to care for both offspring at the same time.

Mexico is objecting to a U.S. decision to negatively certify it for not doing enough to reduce the deaths of endangered sea turtles in fishing nets.

Mexico said it "regrets" the U.S. decision, which could lead to a ban on some Mexican sea products if it doesn't bring protections up to U.S. standards.