The solar system is 4.54 billion years old, based on rock dating. Gas giants (Jupiter and Saturn) likely formed first. Ice giants (Uranus and Neptune) probably formed next. Rocky planets formed ...

Astronomers have discovered a brand new type of planet outside our solar system that, even in its infancy, is already bigger ...

A Jupiter-like planet has been found orbiting a young sun-like star in a solar system far away in what is a potentially ...

A team of astronomers at the University of Arizona played an integral role in uncovering a baby planet with a pretty cute name: WISPIT 2b.

Which planet in our solar system formed first? The question has long been one of the great unsolved mysteries of planetary science. The first planet was almost certainly one of the gas or ice ...

A team led by University of Arizona astronomer Laird Close has discovered a growing planet outside our solar system, marking ...

When most of us left school there were still 9 planets – but we’ve come a long way since Pluto’s demotion. Here’s what’s next on the space agenda.

NASA's Kepler mission has discovered the first Earth-size planets orbiting a sun-like star outside our solar system. The planets, called Kepler-20e and Kepler-20f, are too close to their star to ...