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

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

Planetary systems in the Milky Way galaxy tend to follow a particular pattern: rocky planets toward the center, closest to ...

Astronomers have discovered seeds of rocky planets forming in the gas around the baby sunlike star providing *** peek into the start of our own solar system. The the thing that we've discovered is ...

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

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

By Will Dunham WASHINGTON, Feb 14 (Reuters) - Astronomers have observed a planetary system that challenges current planet ...

When the Sun runs out of hydrogen fuel and expands into a red giant, it will eventually encompass the innermost planets of the solar system, out to about Earth’s orbit. Being closer to our enlarged ...

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit before shoving four of the solar system's planets onto a different course. When ...