It’s the most energetic particle of its kind ever discovered, and scientists have no idea where it came from.

President Trump’s executive order is altering scientific exploration across a broad swath of fields, even beyond government agencies, researchers say.

Alexandra Bell is bringing more than a decade of experience in nuclear policy to the Bulletin of the Atomic Scientists, the organization that sets the Doomsday Clock.

On Monday night you may have a chance to witness the moon obscuring the Red Planet at its brightest, as well as a comet’s closest approach to the sun.

The Quadrantids might be one of the strongest showers this year, but poor weather could make them difficult to see.

The probe sent a signal to Earth indicating that it had survived the closest solar encounter ever attempted by a spacecraft.

Experts said they were “blind” to the Indian Ocean tsunami in 2004. Twenty years later, working toward a world without tsunami deaths is a challenge.