Modern man's forerunners shared the planet with at least two related species nearly two million years ago, scientists said on Wednesday, pointing to newly-unearthed pieces in a 40-year-old fossil puzzle.

Findings published in the journal Nature touch on the odyssey of our ancestor, the upright-walking early human known as Homo erectus.

The United States ran into crossfire on Wednesday after it called for "flexibility" in climate talks, even if this approach could not guarantee meeting the U.N.'s target on global warming.

Europe demanded that the two-degree-Celsius (3.6-degree-Fahrenheit) objective set at the Copenhagen summit in 2009 be honored while small island states accused Washington of dangerous backsliding.

Scientists found that Antarctica was covered by rain forests some 50 million years ago after the analysis of materials taken from the bottom of the ocean in the area, NBC reported.

The scientists said that if the temperatures kept increasing around the world at the current speed, the traces of the plants left under the ice could rise up and Antarctica could become green again.

An Australian medical team and government jet were sent to Antarctica Wednesday to assist in the rescue of an expeditioner from the United States' McMurdo Station base.

The Australian Antarctic Division, a branch of the government's environment department, said the U.S. National Science Foundation had requested assistance in an emergency mission, the details of which were not immediately clear.

A second volcano in New Zealand threatened to rumble to life on Wednesday, a day after a long-dormant mountain that was the backdrop to "The Lord of the Rings" movies erupted.

GNS Science reported no fresh convulsions at the Mount Tongariro volcano, which sent a plume of ash 20,000 feet (6,100 meters) into the atmosphere, showering the North Island and disrupting domestic air travel.

When Bruce Willis used a nuclear bomb to save Earth from a giant asteroid in the movie Armageddon, the scenario had little science and a lot of fiction, physicists said on Tuesday.

Willis' nuke would have had as much impact on the rock as a cheap firecracker and was used so late that the planet would have been doomed anyway, they said.

British physicist and astronomer Bernard Lovell, the creator of what was once the world's biggest radio telescope, has died at the age of 98, his university said Tuesday.

Lovell was the Emeritus Professor of Radio astronomy at Manchester University and the founder and first director of Jodrell Bank Observatory in Cheshire, northwest England.

A Russian booster rocket on Tuesday failed to place two communications satellites into a designated orbit, officials said, marring the prestige of the nation's space program a day after NASA landed a robotic vehicle on Mars.

Russia's Roscosmos space agency said the Proton-M rocket was launched just before midnight Monday from the Russian-leased Baikonur cosmodrome in Kazakhstan. The booster's first stages worked fine, but the upper stage intended to give the final push to the satellites switched off earlier than expected, it said.

Home to lush virgin forest and thousands of elephants, gorillas and rare antelope, the Nouabale Ndoki national park in northern Republic of Congo was virtually unknown until a few weeks ago.

But now the park, given World Heritage status in June by the U.N.'s cultural and science body UNESCO, must live up to the accolade which has raised its profile internationally.

A New Zealand volcano has erupted unexpectedly after lying dormant for more than a century, spewing an ash plume that disrupted flights and closed highways, officials said Tuesday.

The Mount Tongariro volcano, in the middle of North Island, erupted just before midnight (1200 Monday GMT) in the first significant activity at the site since 1897, the official monitoring body GNS Science said.