Add Yahoo as a preferred source to see more of our stories on Google. When you buy through links on our articles, Future and its syndication partners may earn a commission. Planetary scientists are ...

Astronomers have found new evidence that a mysterious ninth planet may be hiding at the edge of the solar system - rewriting what we know about the cosmos again. An international team from ...

An international team of astronomers has discovered a distant planetary system that challenges long-standing theories of how ...

A planetary system 116 light-years from Earth has a peculiar pattern. It could flip the script on how planets form, scientists say.

Add Yahoo as a preferred source to see more of our stories on Google. Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, ...

All of our solar system’s planets are lining up in the night sky at once this week. This extraordinary celestial event will see the sky scattered with seven visible planets in what is known as ...

In our Solar System, the inner planets (Mercury to Mars) are rocky, and the outer planets (Jupiter to Neptune) are gaseous.

Astronomers have discovered the earliest seeds of rocky planets forming in the gas around a baby sun-like star, providing a precious peek into the dawn of our own solar system. It’s an ...

Six planets will briefly share the twilight sky this month - but the conditions have to be just right.

Over the past century, astronomers have speculated about the existence of a mysterious 9th planet lurking in the outer reaches of our Solar System. Although we've never directly observed the elusive ...