Iranian scientist Sirous Asgari has arrived back in Iran after being released from prison by its arch-foe the United States, Iranian media reported Wednesday.

The Tasnim, ISNA and Mehr news agencies all carried the same photograph on their Telegram accounts of Asgari, wearing a face mask against the coronavirus, being reunited with his family.

The multinational team on the biggest Arctic research mission ever undertaken were prepared for problems from polar bear attacks to major snowstorms or even issues with building a runway on ice.

NASA astronauts entered the International Space Station on Sunday after a landmark 19-hour journey on the first crewed US spacecraft in nearly a decade, a triumph for SpaceX and private enterprise.

The World Health Organization on Friday urged countries, companies and researchers to pull down the barriers and open up their findings on COVID-19 as it unveiled a global knowledge-sharing platform.

Dutch authorities on Friday reported the country's first coronavirus case in a dog and infections in three cats, but said chances of contamination through pets were minimal.

Antarctica's king penguins emit such copious amounts of nitrous oxide, or laughing gas, via their feces that researchers went a little "cuckoo" studying them,  according to a Danish scientific study.

"Penguin guano produces significantly high levels of nitrous oxide around their colonies," said the head of the study, Professor Bo Elberling, of the University of Copenhagen's Department of Geosciences and Natural Resource Management.

Scientists the world over are scrambling to perfect an anti-viral treatment for the novel coronavirus, and following what might seem to be some unusual trails.

A host of celebrities and scientists including Madonna, Robert de Niro and a clutch of Nobel Prize winners have called for radical change in the world rather than "a return to normal" after the coronavirus lockdowns.

China said Tuesday it will launch a new spacecraft at 6pm (1000 GMT), in a test of its ambitions to operate a permanent space station and send astronauts to the Moon.

A Russian cargo capsule with 2.5 tons of supplies docked with the International Space Station (ISS) on Saturday after the fastest such trip yet from earth, the national space agency Roscosmos said.