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

Astronomers have found a compact solar system whose planets line up in a way that, according to current models, should not be possible. Around the small star LHS 1903, a dense rocky world orbits on ...

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

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

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

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 ...

Jupiter is the largest planet in our Solar System and the fifth planet from the Sun. It is a massive gas giant made mostly of hydrogen and helium, the same elements that form stars.

Mercury is the smallest planet in our solar system. Explore its size, extreme temperatures, core structure, and comparison with Pluto.