Galileo knew he had discovered a new planet in 1613, 234 years before its official discovery date, according to a new theory by a University of Melbourne physicist. Professor David Jamieson, Head of ...

WASHINGTON (Reuters) - Frigid and far-flung Neptune, our solar system's outermost planet, is adding to its reputation as an enigmatic world, with astronomers puzzled by a surprising drop in its ...

An enigmatic, cloud-enshrouded planet that has puzzled astronomers for years turns out to be less hot than expected – and surprisingly shiny. That's what the James Webb Space Telescope revealed when ...

In 1989, Voyager 2 became the first and only spacecraft to ever fly by Neptune, and images from that mission famously show a planet that's a deep azure color. But in reality, Neptune is far more of a ...

Astronomers used a telescope in Hawaii to find a new object on the outer edges of our solar system, helping to fuel evidence of a long-standing theory about Planet Nine, or Planet X. For years, ...