Australia's weather went "on steroids" over a summer that saw an unprecedented heatwave, bushfires and floods, the climate chief said Monday, warning that global warming would only make things worse.

The Bureau of Meteorology has confirmed the three summer months ending February 28 were the hottest season ever recorded in Australia, leading the government's Climate Commission to label it the "Angry Summer" in a new report.

SpaceX said it was "optimistic" Friday after a thruster outage delayed the latest resupply mission of its unmanned Dragon capsule en route to the International Space Station.

SpaceX and NASA officials said the cargo resupply mission was still on track, but the technical mishap could fuel concerns about the U.S. agency's ambitious plans to cut costs by privatizing elements of the space program.

The U.S. State Department suggested Friday that a $5.3 billion Canada-to-Texas oil pipeline would have no major impact on the environment, but stopped short of recommending it be approved.

The lengthy draft environmental impact statement examines how the Keystone XL Project could affect wildlife and surrounding areas as it crosses from the tar-sands of Alberta in Canada and travels 875 miles (1,408 kilometers) south.

Creating a "superbrain" of connected minds, scientists on Thursday said they had enabled a rat to help a fellow rodent while the animals were a continent apart but connected through brain electrodes.

With electrodes imbedded in its cortex, a rat in a research institute in Natal, Brazil sent signals via the Internet to a counterpart at a university lab in Durham, North Carolina, helping the second animal to get a reward.

Eighteen-year-old Taylor Wilson has designed a compact nuclear reactor that could one day burn waste from old atomic weapons to power anything from homes and factories to space colonies.

The American teen, who gained fame four years ago after designing a fusion reactor he planned to build in the garage of his family's home, shared his latest endeavor at a TED Conference in southern California on Thursday.

International scientists say they've discovered an 18-kilo (40-pound) meteorite in eastern Antarctica, the largest found in that area in 25 years.

The Brussels-based International Polar Foundation said Thursday the meteorite is an "ordinary chondrite," the most common meteorite. It was discovered Jan. 28, and is undergoing a special thawing process in Japan so water won't penetrate it before it's studied.

Levels of carbon dioxide rose hand-in-hand with warming at the end of the last Ice Age, according to a study Thursday that deals a blow to climate skeptics.

French researchers said they had answered a riddle that has perplexed scientists.

There's a new spin on supermassive black holes: They're incredibly fast, astronomers say.

It's long been suspected that gigantic black holes lurking in the heart of galaxies rotate faster and grow larger as they feast on gas, dust, stars and matter. But there hasn't been a reliable measurement of the spin rate of a black hole until now.

Researchers steering a remote-controlled submarine around the world's deepest known hydrothermal vents have collected numerous samples from sunless depths of the Caribbean Sea where blazing hot, mineral-rich fluid gushes from volcanic chimneys that look like gnarled tree stumps.

Jon Copley, chief scientist for the expedition of Britain's National Oceanography Center, said Wednesday he believes that laboratory analysis in the coming months will reveal some new life forms that have evolved in the pitch-black vent areas of the Cayman Trough, more than 3 miles (5 kilometers) below the sea's surface between the Cayman Islands and Jamaica.

The largest genetic study of mental illnesses to date finds five major disorders may not look much alike but they share some gene-based risks. The surprising discovery comes in the quest to unravel what causes psychiatric disorders and how to better diagnose and treat them.

The disorders — autism, attention deficit-hyperactivity disorder or ADHD, bipolar disorder, major depressive disorder and schizophrenia — are considered distinct problems. But findings published online Wednesday suggest they're related in some way.