Earth's magnetic field and oxygen levels have increased more or less in parallel over the past 540 million years, suggesting the two factors are linked in some way, researchers say.

Low iron levels can flip the genetic switch on a mouse's sex during development, causing XY embryos to grow female features. But it's not clear whether the effect applies to humans.

Researchers armed with the Hubble Space Telescope have revealed that some of Uranus' largest moons have one side brighter than the other — but not the side they were expecting.

Space weather experts warn that a "moderate" geomagnetic storm could rock Earth over the weekend, potentially lighting the skies with vibrant auroras across large parts of the U.S. and Europe.

Breathing patterns among humans are so unique that they can work as an identification tool, scientists report. They propose someday using breath as a way to diagnose disease.

The Colorado River basin has lost a Lake Mead’s worth of water in the last 20 years — and scientists say we’re passing a "critical point" where pumping groundwater will become too expensive.