Scientists aboard a research vessel near Los Angeles collected ash, air and water samples as fire blazed on the hills before them in January.

As calls to end fluoride in water get louder, changes to the dental health of children in Calgary, Canada, and Juneau, Alaska, may provide a cautionary tale.

Easy replication in cattle mammary glands means H5N1 bird flu is under no evolutionary pressure to adapt to spread easily in humans.

Societal upheaval can trigger uncertainty, which makes people susceptible to cognitive traps. Experts suggest some simple tools can help.

A weathered sign in the Minnesota River Valley proudly proclaims: “World’s Oldest Rock.” Erected in 1975, it marks a 3.8-billion-year-old gneiss — or so scientists thought.

The first skeletal evidence of a gladiator show or execution involving an exotic animal comes from a Roman British man with bite marks from a lion.

Hubble is still going strong 35 years after it was launched into space. Celebrate its anniversary with some out-of-this-world images.

Warming temperatures can ramp up the activity of methane-producing bacteria in wetland soils, adding to methane emissions.

Autism rates are higher than ever before, probably because of more expansive and sensitive diagnoses. Those numbers highlight the need for more support for people with autism.

Squat rhinos lived in North America about 12 million years ago, congregating in huge, water-bound herds much like modern hippos.

A blob of gas seen outside the Milky Way could be a type of starless, dark matter–dominated galaxy. Some scientists are skeptical.

Rising global temperatures are driving the sharp decline in terrestrial water storage. This trend isn’t likely to change, scientists say.