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

Their observations of a faint, cool M-dwarf star called LHS 1903 revealed a system with a rocky world at its outer edge. LHS ...

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 observed a planetary system that challenges current planet formation theories, with a rocky planet that formed beyond the orbits of its gaseous neighbors, possibly after much of the ...

Six planets are set to align on Saturday, creating a planetary parade that will be visible to sky-gazers across the globe.

A group of astronomers has found a solar system 116 light-years from Earth that seems to challenge current theories about how ...

Astronomers are closing in on one of the most tantalizing possibilities in planetary science, evidence that a previously unknown world may be lurking in the outer reaches of the solar system. The ...

Scientists may have discovered a dwarf planet far beyond Neptune — an unearthing that may disprove a longstanding theory about the possibility of a giant ninth planet. The dwarf planet's existence ...

(CNN) — The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have ...