Planetary systems such as our solar system take hundreds of millions of years to evolve. Since humanity has only existed for a sliver of that time, astronomers have only observed planetary systems at ...

An international team of astronomers has discovered a distant planetary system that challenges long-standing theories of how planets form. Across our galaxy, astronomers routinely observe a ...

The fourth planet in the system is a rocky world, while the second and third ones are gas planets.

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

Astronomers already know how planetary systems are born and how they look once they ...

Nearly all of the solar system’s planets are about to file across the night sky in a planetary alignment, and it will be ...

We know that our Solar System is not the blueprint for all planetary systems out there. There are gas giant planets orbiting closer to their stars than Mercury, and rocky worlds much larger than Earth ...

A rocky exoplanet in the LHS 1903 system defies planet formation models, hinting that gravitational upheaval reshaped the red dwarf’s four worlds.

New research using NASA’s James Webb Space Telescope examines the maximum sizes of gas giant exoplanets, measuring chemical compositions and formation processes in the HR 8799 system.

Add Yahoo as a preferred source to see more of our stories on Google. Digital art of distant planet - Dottedhippo/Getty Images On August 24, 2006, our solar system lost a planet. It wasn't by ...

Add Yahoo as a preferred source to see more of our stories on Google. An illustration showing Planet Nine, a hypothetical, undiscovered planet in our solar system. New research now suggests the ...

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