A long-lost planet that helped create the Moon may have formed much closer to the Sun than scientists once thought, according to new research. Scientists have discovered that Theia, the ancient planet ...

Even at a glance, the planets in our solar system are wildly diverse. Huge and small, airless and densely packed with ...

An artist's impression shows the "inside out" planetary system around the star LHS 1903. - ESA An exoplanetary system about 116 light-years from Earth could flip the script on how planets form, ...

So far, humanity has yet to find its first "exomoon"—a moon orbiting a planet outside of the solar system. But that hasn't been for lack of trying. According to a new paper by Thomas Winterhalder of ...