A planet-size object that possibly once visited the solar system may have permanently changed our cosmic neighborhood by warping the orbits of the four outer planets, a new study suggests.

Kuiper Belt, well past the orbit of Neptune (artistic illustration). There may be an undiscovered planet in the outer solar system whose presence is revealed by the strange orbit of objects beyond ...

Study reveals an interstellar object's impact on planetary orbits, reshaping solar system dynamics. Discover how simulations ...

Why it's so special: This iconic montage features images of Jupiter, Saturn, Uranus and Neptune captured between 2014 and 2024 as part of the Hubble Space Telescope's Outer Planet Atmospheres ...

The Planet Parade of 2025 is a truly extraordinary celestial event that has stargazers excited. From January 21 to ...