Optics

A forthcoming investigational report from an office of the Pentagon has found no evidence of aliens, only allegations circulated repeatedly by UFO claim advocates

A serendipitously discovered object nearly as massive as the Milky Way appears to be made of primordial gas that has formed almost no stars

A new analysis finds that images from Voyager 2's close encounter with Neptune show the planet as being far too blue

Ice crystals suspended in the air put on a gorgeous show if you know when and where to look

Light can be reflected not only in space but also in time—and researchers exploring such “time reflections” are finding a wealth of delightfully odd and useful effects

Money, engineering and sheer geometry may mark an end of the line for building ever larger astronomical telescopes

Fresh images show off the Euclid space telescope’s ability to capture crisp pictures of vast swaths of sky

The James Webb Space Telescope is gazing across the universe to find galaxies close to the “cosmic dawn”—and you can explore them from the palm of your hand

The darkness of the night sky offers a profound insight on the nature of the cosmos

A surprisingly complex galaxy cluster suggests that in the search for dark matter, nothing is as simple as it seems

A colorful quirk of quantum optics could lead to significant advances in quantum communication and computing

This annular solar eclipse will only reveal its full glory to a select few, but onlookers across much of the Western Hemisphere can catch a partial glimpse of the dazzling phenomenon