An astronaut on the International Space Station captured mysterious blue spheres in the sky last year. NASA’s Earth Observatory shared the photo last year, as well, shortly after it was taken ...

Inspired by a floating droid battling Luke Skywalker in the film Star Wars, the free-flying satellites known as Synchronized Position Hold, Engage, Reorient, Experimental Satellites (SPHERES) have ...

The two spheres spotted by Yutu 2 (Image credit: Xiao et al., Science Bulletin) China 's Yutu-2 rover has spotted two strange glass spheres on the far side of the moon.

If you're struggling, don't despair. Figuring out how to weigh (well, measure the mass) of the Earth took until 1687, and even then we couldn't calculate it until 1798.. At the end of the 1600s ...