Venerated for 150 years as the forebear of all birds until being relegated two years ago to the common class of winged dinosaurs, the Archaeopteryx was restored to its hallowed branch on the tree of life on Wednesday.

A fossil find in China proved the winged creature was in fact an ancestor of modern birds, said a study in the journal Nature.

Similar in size and often referred to as twin planets, Earth and Venus evolved from common origins into two contrasting worlds - one dry and inhospitable, the other wet and teeming with life.

The reason has had science stumped, until now.

Plants entombed under ice in Canada's far north for centuries have come back to life after exposure to air and sunlight, Canadian researchers have found.

University of Alberta researcher Catherine La Farge collected what she believed to be dead mosses (or bryophytes) from the foot of a retreating glacier in Sverdrup Pass on Ellesmere Island.

Russian scientists claimed Wednesday they have discovered blood in the carcass of a woolly mammoth, adding that the rare find could boost their chances of cloning the prehistoric animal.

An expedition led by Russian scientists earlier this month uncovered the well-preserved carcass of a female mammoth on a remote island in the Arctic Ocean.

An international trio flying in a Russian capsule docked with the International Space Station on Wednesday with a busy schedule full of space walks and an encounter with a pioneering U.S. cargo craft.

The six-month mission of Russian commander Fyodor Yurchikhin and his two flight engineers -- Karen Nyberg of NASA and Italian Luca Parmitano of the European Space Agency -- began once their craft sidled up to the orbiting lab six hours after blasting off from the Moscow-owned Baikonur space center in Kazakhstan.

Three scientists whose groundbreaking studies using fruit flies helped to uncover the workings of the human biological clock were Tuesday named the winners of the $1 million Shaw Prize.

U.S. scientists Jeffrey Hall, Michael Rosbash and Michael Young received the award "for their discovery of molecular mechanisms underlying circadian rhythms", the prize organizers said in a statement.

With too many people chucking their garbage into neighbors' bins -- or worse, the woods -- to avoid paying for disposal, Poland has taken on a massive overhaul of its laissez-faire waste management system.

The new greener setup, which enters into force in July, will lower the incentive to litter by requiring everyone to pay a municipal disposal tax for a service that up to now has been left up to each household to coordinate.

A huge haul of illegal ivory in China has revealed the vast scale of the trade and flaws in the country's system of legal ivory sales, a wildlife monitoring group said.

A court heard that authorities seized a total of 7.7 tonnes of ivory on a series of occasions in 2011, reports said last week, and three people were jailed for terms ranging from seven to 15 years in connection with the case.

The number of researchers exposed to low-level radiation in an accident at a nuclear laboratory in Japan last week has hit 30, officials said Monday, with human error likely worsening the problem.

The accident happened on Thursday as 55 people were working at a laboratory in Tokaimura, 120 kilometers (75 miles) northeast of Tokyo, the Japan Atomic Energy Agency (JAEA) said.

Minerals found in craters on the Moon may be remnants of asteroids that slammed into it and not, as long believed, the satellite's innards exposed by such impacts, a study said Sunday.

The findings, published in the journal Nature Geoscience, cast doubt on the little we knew of what the Moon is actually composed of.