Nuclear engineers in Japan are preparing to move uranium and plutonium fuel rods at Fukushima, their most difficult and dangerous task since the plant's runaway reactors were brought under control two years ago.

Tokyo Electric Power (TEPCO) is expected this month to begin removing fuel rods from a pool inside a reactor building at the tsunami-hit plant after months of setbacks and glitches.

U.N. climate talks resume in Warsaw on Monday amid a slew of warnings about a potentially disastrous rise in greenhouse-gas emissions.

Though the stakes are high, no specific targets have been set for this round, hosted by one of the world's biggest coal polluters just two years before the tortuous global process must deliver a new deal.

India's Mars spacecraft has completed the first of a series of engine firings designed to free it from Earth's gravitational pull and propel it towards the Red Planet, scientists said Friday.

The first "orbit-raising manoeuvre", which involves the firing of a liquid fuel thruster, was performed Thursday followed by the second firing on Friday, the Indian Space Research Organisation (ISRO) said.

The European Union moved closer to approving the cultivation of a second genetically modified corn on the continent despite years of objections by environmental groups and widespread apprehension about GMO food among European consumers.

Wednesday's approval by the EU Commission, the bloc's executive arm, now sends the plan to approve DuPont-Pioneer Maize 1507 to the EU's 28 member nations for consideration — and could lead to a decision on the issue within months.

The asteroid that smashed into the central Russian city of Chelyabinsk initially measured 19 meters (61 feet) across, packing the energy of dozens of Hiroshima bombs, a study said on Wednesday.

Scientists in the Czech Republic and Canada analysed video and audio footage and fragments recovered from the dramatic incident on February 15.

Chinese scientists have discovered the oldest known fossil of a pair of insects caught in the act of copulating, according to a study released Wednesday.

The imprint of the male and female froghoppers, lying belly to belly, was dug up in northeastern China. The fossil is believed to be 165 million years old, said the report in the journal PLOS ONE.

Paleontologists on Wednesday unveiled a new dinosaur discovered in the U.S. that proves giant tyrant dinosaurs like the Tyrannosaurus rex were around 10 million years earlier than previously believed.

A full skeletal replica of the carnivore — the equivalent of the great uncle of the T. rex — was on display at the Natural History Museum of Utah alongside a 3-D model of the head and a large painted mural of the dinosaur roaming a shoreline.

The world's first robot astronaut is pining for a conversation partner as he waits for Japanese spaceman Koichi Wakata aboard the International Space Station.

"Mr. Wakata, are you not here yet? I really want to see you soon," the pint-sized android said in a message released by its project team in Japan Wednesday.

Decomposed whale carcasses have been washing up on beaches in Ghana's oil-producing west, raising the ire of environmental groups worried the country's growing petroleum industry may be killing marine life.

A total of 20 dead whales have been discovered along Ghana's coastline in the last four years, including at least eight since September.

The amount of greenhouse gases in Earth's atmosphere hit a new record high in 2012, continuing an ever-faster rise that is driving climate change, the U.N. weather agency said Wednesday.

"The concentrations are reaching once again record levels," Michel Jarraud, who heads the World Meteorological Organization (WMO), told reporters in Geneva.