The gas flowing into these black holes became hot enough to glow brightly before it disappeared. The light of these "quasars" can be seen across the depths of the universe. Within galaxies ...

Stars form in regions of space known as stellar nurseries, where high concentrations of gas and dust coalesce to form a baby ...

Like stretch marks left on skin that expanded too quickly or cracks embedded in freezing ice, cosmic strings are artifacts of what the universe looked like in the moments before it rapidly changed ...

image has helped astronomers untangle a long-standing mystery about how planets form. The mystery arose more than 20 years ago, when the Hubble Space Telescope spotted the universe's oldest known ...

These theories aim to address questions the Big Bang does not fully resolve, keeping the debate about the universe’s origins alive and dynamic. Related: What happened before the Big Bang?

a hypothetical form of matter that is massive, electrically neutral and hardly, if ever, interacts with normal matter. This dark matter makes up most of the mass in the universe, far outweighing ...