Circus bear Mura wound up in the world's biggest brown bear sanctuary in the heart of Romania's Carpathian mountains after refusing to perform any longer, following five years of unbearable abuse.

Caged, beaten and starved by their owners, 80 bears rescued from captivity have been taken in to be healed of trauma at the "Libearty" sanctuary, but the process can be slow.

British cosmologist Stephen Hawking on Monday launched the biggest-ever search for intelligent life in the universe in a 10-year, $100-million (143-million-euro) project to scan the heavens.

The Breakthrough Listen project, backed by Russian Silicon Valley entrepreneur Yuri Milner, will be the most powerful, comprehensive and intensive scientific search ever undertaken for signs of extra-terrestrial intelligent life.

Artur Bilsky's Institute of Thermophysics recently sought to buy equipment from a Japanese company that was a routine purchase a few years ago. The request was turned down "categorically," said Bilsky, a researcher at the institute.

Hundreds of other Russian scientists are reporting similar experiences of being refused sale of scientific equipment from abroad, or seeing research papers curtly turned down by Western publications. The reason, they believe, is a combination of sanctions against Russia over its actions in Ukraine and rising hostility to Russia in the West seeping into the scientific community.

The National Air and Space Museum is launching a crowdfunding campaign to conserve the spacesuit Neil Armstrong wore on the moon.

The campaign begins Monday, marking 46 years since Armstrong's moonwalk in 1969. Conservators say spacesuits were built for short-term use with materials that break down over time.

Europe's robot lab Philae has fallen "silent" on the surface of a comet zipping towards the Sun, said ground controllers Monday who fear it may have shifted out of radio contact.

"The lander could have moved," the German Aerospace Center (DLR) said in a statement, adding: "even a slight change in its position could mean that its antennas are now obstructed".

With space shuttles now housed in history museums, innovators in aerospace are thinking of newer, better ways humans could reach space. One idea: What about a space elevator?

This real idea is one simulation that's part of a new high-tech interactive exhibition about the future of flight opening Aug. 1 at the Smithsonian's National Air and Space Museum. The exhibit also will serve as an important test case for new technologies to overhaul the popular museum with more interactives.

Japan, the world's sixth biggest greenhouse gas polluter, has pledged to cut emissions 26 percent from 2013 levels by 2030, a target observers judged inadequate to avert calamitous global warming.

In order to achieve this goal, nuclear energy, deeply unpopular and offline since the 2011 tsunami-induced Fukushima disaster, must provide about 20-22 percent of electricity production by then, said the country's official UN filing late Friday.

Smooth, icy plains have been spotted on the surface of Pluto, in the latest images released Friday from a NASA spacecraft that flew by the dwarf planet this week.

The plains are located north of Pluto's icy mountains, in the center-left of the heart shape that NASA has named "Tombaugh Regio," or the Tombaugh Region after Clyde Tombaugh, who discovered Pluto in 1930.

A super-dense white dwarf star about 730 light years from Earth has been caught in the act of "cannibalizing" its companion, astronomers said Friday.

The pair form a binary star system named Gaia14aae after the European Space Agency's Gaia satellite which discovered it in August 2014.

Guatemalan security forces rescued 52 animals from endangered species, including several dozen macaws and some turtles, during a raid in which they arrested two alleged wildlife traffickers, an official said Thursday.

The animals were rescued from a construction company in the town of Amatitlan, just south of Guatemala City, national police spokesman Jorge Aguilar told reporters.