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

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 ...

A newly identified planet candidate, HD 137010 b, looks strikingly Earth-like in size and orbit — but it may be colder than Mars due to its dimmer star. If it has a thick enough atmosphere, though, ...

Six planets—including Venus, Jupiter, and Mercury—will line up in the sky. Here’s the best time to watch and where to find clear views.

Astronomers have uncovered a distant planetary system that flips a long-standing rule of planet formation on its head. Around the small red dwarf star LHS 1903, scientists expected to find rocky ...