Calgary Zoo polar bear drowns after rough play incident

A necropsy has confirmed that a polar bear at the Calgary Zoo died after rough playing with another polar bear.

Pets can smell your stress, study finds

A new study reveals that dogs can detect human stress through their sense of smell, reacting emotionally to higher levels of the hormone cortisol in sweat.

Study: Wildfire smoke may be worse for your brain than other air pollution

Research shows wildfire smoke significantly raises dementia risk, with a 21% increase per 1 microgram of PM2.5, compared to other air pollution.

Surfer loses leg in fight with 10-foot great white shark

After the attack, Kai McKenzie managed to make it back to shore and his leg also washed ashore not long after.

Watch: Swarm of dragonflies invades Rhode Island beach, sends visitors fleeing

A relaxing day turned chaotic for beachgoers in Westerly, Rhode Island, as a massive swarm of dragonflies invaded Misquamicut State Beach on Saturday.

Watch: Mountain goat shows off dance moves on top of Subaru

A hiker in Colorado walked back to her car only to find two mountain goats having a party on the roof of her Subaru without her.

Geomagnetic storm watch: Did you see northern lights auroras this week? Here’s why

A geomagnetic storm watch predicted northern lights visibility as far south as New York this week. Learn what caused this rare celestial event and its potential impacts.

NASA: No return date yet for astronauts aboard ISS

Two NASA astronauts aboard the International Space Station were supposed to come back to Earth in mid-June, but ongoing issues with their Boeing Starliner capsule have extended their stay.

Sharks test positive for cocaine off Brazil's coast

Sharks have tested positive for cocaine off Brazil’s coast, according to a new scientific study.

Pig hearts and kidneys: Barns may be future of organ transplantation

Some of the world's cleanest pigs are being raised in the Virginia mountains to supply kidneys and hearts for animal-to-human organ transplants.