Richard Barclay opens a metal drawer in archives of the Smithsonian Natural History Museum containing fossils that are nearly 100 million years old. Despite their age, these rocks aren't fragile. The geologist and botanist handles them with casual ease, placing one in his palm for closer examination.

Embedded in the ancient rock is a triangular leaf with rounded upper lobes. This leaf fell off a tree around the time that T-rex and triceratops roamed prehistoric forests, but the plant is instantly recognizable. "You can tell this is ginkgo, it's a unique shape," said Barclay. "It hasn't changed much in many millions of years."

France's pharmaceutical giant Sanofi, which has lagged behind rivals in developing new generation mRNA Covid-19 vaccines, on Tuesday said it has purchased a U.S. firm specializing in the technology.

Sanofi will buy Translate Bio, with which it has been working to develop an mRNA Covid jab, for $3.2 billion (2.7 billion euros), the company said in a statement.

Imagine a Covid-19 vaccine that came as a pill: no needles, no medical professionals required to administer it, potentially delivered directly to people's homes. 

Two Sumatran tigers were recovering at a Jakarta zoo after being infected with coronavirus, Indonesian officials said Sunday, as they probed how the critically endangered animals got sick.

Indonesia's Mount Sinabung erupted on Wednesday, spewing a massive column of smoke and ash into the sky.

The eruption of the volcano in North Sumatra province lasted about 12 minutes, a local geological agency said.

Nearly 200 nations started online negotiations Monday to validate a U.N. science report that will anchor autumn summits charged with preventing climate catastrophe on a planetary scale. 

"The report that you are going to finalize is going to be very important worldwide," World Meteorological Organization head Petteri Taalas told some 700 delegates by Zoom.

Imagine multi-colored pinwheel fireworks, but on a galactic scale.

That is exactly what images of baby stars that European astronomers released Friday look like. 

A Chinese spacecraft carrying three astronauts successfully docked with the country's space station on Thursday afternoon, its space agency said, around seven hours after blasting off.

Astronauts blasting off on Thursday for China's first manned mission to its new space station will have a choice of 120 different types of food and "space treadmills" for exercise during their stay, China's space agency said.

A large segment of a Chinese rocket re-entered the Earth's atmosphere and disintegrated over the Indian Ocean on Sunday, the Chinese space agency said, following fevered speculation over where the 18-ton object would come down.