A recent, 14-year dry spell in the Middle East was the worst drought in the past 900 years, according to a new NASA study released this week.

NASA's researchers examined records of rings of trees in several Mediterranean countries to determine patterns of dry and wet years across a span of 900 years. They concluded that the years from 1998 to 2012 were drier than any other period, and that the drought was likely caused by humans.

Conservation group Greenpeace warned on Friday that the environmental impact of the Fukushima nuclear crisis five years ago on nearby forests is just beginning to be seen and will remain a source of contamination for years to come.

The March 11, 2011 magnitude 9.0 undersea earthquake off Japan's northeastern coast sparked a massive tsunami that swamped cooling systems and triggered reactor meltdowns at the Fukushima Daiichi nuclear plant.

Social media sites such as Facebook and Instagram are increasingly being used in Asia as platforms for the illegal trade in threatened species ranging from rare birds to orangutan and sun bears, conservation groups said Thursday.

The trend poses a new and worrying threat in a tech-savvy region where products derived from endangered species are sought for traditional medicines and exotic animals are prized as pets, said wildlife-trade monitor Traffic and conservation group WWF.

U.S. astronaut Scott Kelly and Russian cosmonaut Mikhail Kornienko returned to Earth Wednesday after spending almost a year in space in a ground-breaking experiment foreshadowing a potential manned mission to Mars.

The 340-day mission saw Kelly break the record for the longest single stay in space by a U.S. astronaut, while Kornienko is now fifth on the list for lengthiest mission by a Russian cosmonaut.

In the very last second before liftoff Sunday, SpaceX scrubbed the launch of its Falcon 9 rocket to send a communications satellite into orbit, marking the third delay since last week.

A fuel problem forced the sudden delay, following a postponement -- known as a hold -- earlier in the evening due to a ship that ventured into the waters off Cape Canaveral, Florida, said SpaceX CEO Elon Musk.

The sun-powered plane Solar Impulse 2 has made a successful test flight in Hawaii, where it has been grounded for repairs on its round-the-world trek, the Swiss-based project said Saturday.

"The first Solar Impulse 2 maintenance flight took place on Friday 26 of February (and) was uneventful. The plane took off from Kalaeloa airport at 4:32PM UTC [GMT] with our test pilot, Markus Scherdel, in the cockpit, and landed at 6:05PM UTC," it said on its blog.

An Australian icebreaker that ran aground in Antarctica during a blizzard has been refloated, officials said Saturday as they work to bring the vessel's expeditioners home.

The Aurora Australis ran aground with 68 people on board after breaking its moorings on Wednesday and was stuck on rocks at Horseshoe Harbor, close to Australia's Mawson station.

The monarch butterfly population has soared in its Mexican winter sanctuary this season, marking a recovery for the threatened species that migrates across North America, officials said Friday.

The orange and black butterfly covered 4.01 hectares (9.9 acres) of pine and fir forest in the 2015-2016 season, more than tripling last year's figure of 1.13 hectares, Mexican, U.S. and Canadian officials said.

Populations of bees, butterflies and other species important for agricultural pollination are declining, posing potential risks to major world crops, a U.N. body on biodiversity said Friday.

"Many wild bees and butterflies have been declining in abundance, occurrence and diversity at local and regional scales in Northwest Europe and North America," said an assessment by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES).

An endangered tiger was shot dead by security forces in eastern Myanmar Thursday after it attacked local fishermen as they tended their nets, the state military newspaper reported.

Soldiers and local authorities hunted the animal "to prevent danger to villagers" after it mauled the two men in the early hours of the morning, the army's Myawaddy paper said in a post on its Facebook page.