Euclid, a space telescope on a mission to uncover the secrets of dark matter and dark energy, has already made a stunning discovery: a perfectly formed Einstein ring hidden in a well-known galaxy.

Euclid blasted off on its six-year mission to explore the dark universe on 1 July 2023. Before the spacecraft could begin its ...

"They're so rare, and they're incredibly useful scientifically," said Conor O'Riordan of the Max Planck Institute for Astrophysics.

Albert Einstein himself thought that the eponymous Einstein ring would be impossible to observe, but the Euclid telescope has ...