Euclid space telescope sent some images back to Earth during an early testing phase. While reviewing the pictures, astronomer ...

Galactic lenses like this one, which is the closest astronomers have ever found, were predicted by Albert Einstein in 1936 ... makes it easier to see the four images of the faraway galaxy.

The dividing line between the inside and outside of a black hole is called the event horizon. Anything crossing the horizon—a star, a planet, a person—is lost forever. Albert Einstein ...