A compound lens forged by two galaxies is helping astronomers get a bead on the Hubble Constant and dark energy.

An international team of astronomers has discovered an instance of two galaxies aligned in a way where their gravity acts as ...

Not only that, but the second lens also magnifies the first – though not very bright, it can be seen in the images collected ...

However, if you're interested in more than just lunar phases, a telescope can allow lunar mare (large plains formed by lava) to come into focus and the moon's many impact craters to pop out. More ...