In the late eighth century, Earth was hit by a mystery blast of cosmic rays, according to a Japanese study that found a relic of the powerful event in cedar trees.

Analysis of two ancient trees found a surge in carbon-14 -- a carbon isotope that derives from cosmic radiation -- which occurred just in AD 774 and AD 775, the team report in the journal Nature on Sunday.

The French government is to ban a pesticide made by Swiss giant Syngenta used in rapeseed cultivation that has been found to shorten bees' lifespan, Agriculture Minister Stephane Le Foll said Friday.

"I have warned the group that sells Cruiser that I envisage withdrawing the licence to market," Le Foll said after the National Food, Environment and Work Safety Agency (ANSES) issued a damning report on the pesticide.

UNESCO on Saturday urged decisive action from Australia to protect the Great Barrier Reef from a gas and mining boom, warning it risked being put on its list of world heritage sites deemed "in danger".

Australia is riding an unprecedented wave of resources investment due to booming demand from Asia, with projects worth Aus$450 billion (U.S. $435 billion) in the pipeline.

Nearly a year after they joined the periodic table, two man-made elements have been officially named.

What used to be element 114 is now flerovium, honoring the Flerov Laboratory of Nuclear Reactions in Dubna, Russia, where it was created. Element 116 is now livermorium, for the Lawrence Livermore National Laboratory in Livermore, Calif., home of a scientific team that participated in its creation in Dubna. The chemical symbols are Fl and Lv.

U.S. company SpaceX's cargo vessel Thursday splash landed in the Pacific Ocean, capping a successful mission to the International Space Station that blazed a new path for private spaceflight.

"This really couldn't have gone better," said SpaceX chief executive Elon Musk after the unmanned capsule landed in the waters off the Mexican coast at 11:42 am Eastern time (1542 GMT).

Our galaxy is on a collision course with its nearest neighbor, Andromeda, and the head-on crash is expected in four billion years, the U.S. space agency NASA said on Thursday.

Astronomers have long theorized that a clash of these galaxy titans was on the way, though it was unknown how severe it might be, or when, with guesses ranging from three to six billion years.

The world's air has reached what scientists call a troubling new milestone for carbon dioxide, the main global warming pollutant.

Monitoring stations across the Arctic this spring are measuring more than 400 parts per million of the heat-trapping gas in the atmosphere. The number isn't quite a surprise, because it's been rising at an accelerating pace. Years ago, it passed the 350 ppm mark that many scientists say is the highest safe level for carbon dioxide. It now stands globally at 395.

Harvard University scientists on Wednesday said they had created Smileys, Chinese characters and card-game symbols at scales of billionths of a meter using strands of DNA.

The feat marks the next step in "DNA origami" in which the molecule that provides the genetic code for life is used as a building block at the nanoscale, with potential outlets in engineering and medicine.

The U.S. space agency said Wednesday it is preparing to launch next month a sophisticated orbiting telescope that will use high energy X-ray vision to hunt for black holes in the universe.

The project aims to study the "hottest, densest and most energetic phenomena in the universe, like for example black holes and the explosions of massive stars," said Fiona Harrison, principal investigator for the Nuclear Spectroscopic Telescope Array (NuSTAR).

Astronomers around the world will be using advanced telescopes to watch Venus cross in front of the Sun on June 5 and 6 in the hopes of finding clues in the hunt for other planets where life may exist.

By studying the atmosphere of a well-known planet in this once-in-a-lifetime event, scientists say they will learn more about how to decipher the atmospheres of planets outside our solar system as they cross in front of their own stars.