The United States is turning to new drugs for lethal injections as supplies of the current standard dwindle, sparking lawsuits from death row prisoners that the changes will cause undue suffering.

Two men were put to death Wednesday in Texas and Arizona, using a lethal dose of an animal anesthetic customized by a compounding pharmacy -- which has not been approved at the federal level.

Russian Prime Minister Dmitry Medvedev on Thursday replaced the head of the state space agency Roscosmos after a series of high-profile setbacks including a deeply embarrassing rocket explosion upon takeoff.

Oleg Ostapenko, previously deputy defense minister, was appointed the new chief, replacing Vladimir Popovkin who lasted only 2.5 years at the post.

Three U.S.-based scientists won a Nobel Prize on Wednesday for developing a powerful new way to do chemistry on a computer.

They pioneered highly sophisticated computer simulations of complex chemical processes, giving researchers tools they are now using for a wide variety of tasks, such as designing new drugs and solar cells.

Earth may experience a radically different climate already within 34 years, forever changing life as we know it, said a study Wednesday that aims to bring the dangers of global warming into sharper focus.

On current trends of greenhouse-gas emissions, 2047 will mark the year at which the climate at most places on Earth will shift beyond documented extremes, it said.

Astronomers said Wednesday they have found a lonely planet outside the solar system floating alone in space and not orbiting a star.

The gaseous exoplanet, dubbed PSO J318.5-22, is just 80 light years from Earth and has a mass only six times that of Jupiter. Having formed 12 million years ago, the planet is considered a newborn among its peers.

Minamata was the site of Japan's worst ever industrial poisoning and is regarded as the dark side of Japan's rapid modernization during the 20th Century.

For decades, a synthetic resin factory run by chemical company Chisso Corp had been dumping methylmercury into the bay of the town on southwestern Kyushu island, poisoning the marine habitat.

Three years ago, French researchers declared that a centuries-old mummified head was that of the beloved King Henri IV. But now a new study says, "Non!"

The original conclusion was based largely on facial reconstruction techniques and signs the skull had injuries similar to those suffered by the monarch. The new study looked at DNA instead.

A NASA spacecraft bound for Jupiter will swing by Earth on Wednesday to get the boost it needs to arrive at the giant gas planet in 2016.

Using Earth as a gravitational slingshot is a common trick since there isn't a rocket that's powerful enough to catapult a spacecraft directly to the outer solar system.

The government shutdown in Washington has forced U.S. bases half a world away in Antarctica to suspend research as they go into "caretaker" mode, the National Science Foundation (NSF)said Wednesday.

In an unprecedented development that scientists described as "tragic", the U.S.-based foundation said logistical support funding for the US Antarctic Program (USAP) will dry up early next week and contractors have been ordered to scale back operations.

The Nobel Prize in Physics should also have gone to the CERN laboratory in Switzerland, a member of the awarding committee said Wednesday.

"I think it's wrong," Anders Barany, a member of the Royal Swedish Academy of Sciences told Agence France Presse, commenting after the decision Tuesday, which was delayed for an hour due to "a lot of discussion."