How do we know the speed of light – and why does it have a speed limit at all? Leah Crane explores the history of one of the most important numbers in the universe ...

Astronomers are rethinking one of cosmology’s biggest mysteries: dark energy. New findings show that evolving dark energy models, tied to ultra-light axion particles, may better fit the universe’s ...

I/ATLAS showed signs of non-gravitational acceleration as it passed near the sun, attracting global scientific attention.