A "mega den" of hundreds of rattlesnakes in Colorado is getting even bigger now that late summer is here and babies are being born.

Thanks to livestream video, scientists studying the den on a craggy hillside in Colorado are learning more about these enigmatic — and often misunderstood — reptiles. They're observing as the youngsters, called pups, slither over and between adult females on lichen-encrusted rocks.

Italian researchers have noted the first case of "virgin birth", or reproduction without fertilization, in an endangered shark species, a scientific journal reported this week.

The findings published in Scientific Reports concern the first case of the phenomenon in the common smooth-hound shark, Mustelus mustelus, a species threatened by illegal fishing that inhabits the Mediterranean and other warm waters.

Japanese scientists have used human cells to develop an equivalent to living skin that can be attached to robotic surfaces to flash a realistic -- if creepy -- smile.

China's space officials said Thursday they welcomed scientists from around the world to apply to study the lunar rock samples that the Chang'e 6 probe brought back to Earth in a historic mission, but noted there were limits to that cooperation, specifically with the United States.

Officials said at a televised news conference in Beijing meant to introduce the mission's achievements that any cooperation with the U.S. would be hinged on removing an American law that bans direct bilateral cooperation with NASA.

China's Chang'e 6 probe returned on Earth with rock and soil samples from the little-explored far side of the moon in a global first.

The probe landed in the Inner Mongolian region in northern China on Tuesday afternoon.

A sonic boom heard in Tuscany and on the French island of Corsica, initially mistaken by holidaymakers, locals and officials for an earthquake, may have been a meteorite, experts said.

The town of Campo nell'Elba, on the Italian tourist island of Elba, said on its Facebook page that a nearby tracking station had "captured a seismic, acoustic event felt by everyone" at 4:30pm (1430gmt).

A French-Chinese telescope satellite will blast off this weekend on a mission to hunt down gamma-ray bursts, the most powerful explosions in the universe.

After years of stumbles and delays, Boeing has finally launched astronauts to the International Space Station for NASA.

It's the first flight of Boeing's Starliner capsule with a crew on board, a pair of NASA pilots who will check out the spacecraft during the test drive and a weeklong stay at the space station.

The James Webb Space Telescope has discovered what appears to be a new record-holder for the most distant known galaxy, a remarkably bright star system that existed just 290 million years after the Big Bang, NASA said Thursday.

New research indicates the sun's magnetic field originates much closer to the surface than previously thought, a finding that could help predict periods of extreme solar storms like the ones that slammed Earth earlier this month.

The magnetic field appears to generate 20,000 miles (32,000 kilometers) beneath the sun's surface. Previous calculations put the roots of this process more than 130,000 miles (209,000 kilometers) below, an international team reported Wednesday.