The Solar Impulse 2 plane touched down in Tulsa, in the south-central U.S. state of Oklahoma late Thursday, ending the latest stage of its record-breaking quest to circle the globe without consuming a drop of fuel.

The experimental solar-powered aircraft, aimed at promoting clean energy technologies, landed at 11:17 pm local time (0417 GMT) at Tulsa International Airport after taking off at 3:00 am (1000 GMT) from Phoenix, Arizona, live feed showed.

The Solar Impulse 2 plane took off from Phoenix, Arizona en route to Oklahoma on Thursday, resuming its record-breaking quest to circle the globe without consuming a drop of fuel.

Allowing the legal culling of wild wolves in order to discourage illegal poaching is counter-productive, researchers reported Wednesday in a study that challenges long-practiced conservation strategy.

During a 15-year period when wildlife management policies in two US states flipped half-a-dozen times, growth in wolf populations slowed systematically whenever culling was permitted, even after controlling for the number of animals legally killed, they found.

Astronomers celebrated Monday witnessing one of the highlights of the skywatchers' year, when the Sun, Mercury and Earth all lined up -- a phenomenon that happens just a dozen or so times per century.

Mercury was seen through telescopes as a black dot inching over the face of our star, providing a celestial spectacle lasting seven and a half hours.

Scientists unveiled Monday the gene in carrots that gives rise to carotenoids, a critical source of Vitamin A and the pigment that turns some fruits and vegetables bright orange or red.

The world's most powerful proton smasher is preparing for its biggest run yet which scientists hope will uncover new particles that could dramatically change our understanding of the Universe.

SpaceX successfully landed the first stage of its Falcon 9 rocket on a floating platform in the Atlantic Ocean early Friday after launching a Japanese communications satellite into orbit.

A bug over half a meter long discovered in southern China has been declared the world's longest insect, state media said Thursday.

SpaceX plans to launch early Friday a Japanese communications satellite into a distant orbit before attempting to land the first stage of its Falcon rocket on a floating platform in the Atlantic Ocean.

The liftoff is scheduled for 1:21 am (0521 GMT) from Cape Canaveral, Florida, the California-based company headed by Internet entrepreneur Elon Musk said.

An international team of scientists said Monday they had discovered a trio of Earth-like planets that are the best bet so far for finding life outside our solar system.

The three orbit an ultracool dwarf star a mere 39 light years away, and are likely comparable in size and temperature to Earth and Venus, they reported in a study, published in Nature.