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

Astronomers have long believed that planetary systems follow a familiar blueprint. Small rocky planets ...

Gas giants are large planets mostly composed of helium and/or hydrogen. Although these planets have dense cores, they don't ...

Deep in the older, denser reaches of the Milky Way, there is a red dwarf star that shouldn’t exist — or at least, its family ...

Gas giants possibly developed slowly in the solar system. They developed cores layer by layer within a disk of ice and dust ...

Scientists have identified a rocky outer planet in a system where a gas giant was expected. The discovery challenges ...

Since the 1990s, scientists have discovered approximately 6,100 planets outside our solar system, called exoplanets.

Rogue planets may be more common than we thought, and they may form alone in the void in the same way stars do, suggests a recent study. We think we know how the universe is structured: Moons orbit ...

A newly studied solar system breaks the usual planet pattern, raising fresh questions about how rocky and gas planets form.

Astronomers have found a distant world that challenges planetary formation theory, with a rocky planet where gas giants should be.

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. (Left) the ringed gas giant ...