The winter solstice is Saturday, bringing the shortest day and longest night of the year to the Northern Hemisphere — ideal conditions for holiday lights and warm blankets.

For those who would rather have more sunlight, you can try to make your way to the Southern Hemisphere, where it is summer. Or be patient: Starting Sunday, days will get a little bit longer in the Northern Hemisphere every single day until late June.

The U.S. has updated a decades-old science and technology agreement with China to reflect their growing rivalry for technological dominance. The new agreement, signed Friday after many months of negotiations, has a narrower scope and additional safeguards to minimize the risk to national security.

The State Department said the agreement sustains intellectual property protections, establishes new guardrails to protect the safety and security of researchers and "advances U.S. interests through newly established and strengthened provisions on transparency and data reciprocity."

Scientists suspect the first complete specimen ever recorded of the world's rarest whale died from head injuries, an expert said Friday.

The first dissection of a spade-toothed whale, a type of beaked whale, was completed last week after a painstaking examination at a research center near the New Zealand city of Dunedin, the local people who led the scientific team, Te Rūnanga Ōtākou, said in a statement issued by the New Zealand Department of Conservation.

Distant, ancient galaxies are giving scientists more hints that a mysterious force called dark energy may not be what they thought.

Astronomers know that the universe is being pushed apart at an accelerating rate and they have puzzled for decades over what could possibly be speeding everything up. They theorize that a powerful, constant force is at play, one that fits nicely with the main mathematical model that describes how the universe behaves. But they can't see it and they don't know where it comes from, so they call it dark energy.

A small, bright meteor lit up skies over the northern Philippines early Thursday as it burned up entering the Earth's atmosphere, the European Space Agency and witnesses said.

A spacecraft carrying European and Japanese probes passed closer to Mercury than originally planned overnight after thruster problems delayed the mission to study the little-known, Sun-scorched planet.

South Korea's new space agency said Thursday it was looking to grow its share of the industry and take on Elon Musk's SpaceX, as it unveiled plans to create a "space passageway".

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.