A new trail in this southern Arizona city plots the most visitor-friendly astronomy stops—and there are plenty to choose from ...

Euclid, a European space telescope, just captured 26 million galaxies to reveal the secrets of the dark universe.

National Geographic Explorer Paul Salopek has covered a lot of ground: some 14,000 miles — on foot — through 21 countries so ...

Most states along the Canadian border could see the northern lights Monday night, as auroral activity is expected to calm ...