Using NASA's Transiting Exoplanet Survey Satellite (TESS), an international team of astronomers has discovered a new ...

There may be a warp in the Kuiper Belt, possibly caused by “Planet Y” — a Mercury-to-Earth-sized world that orbits the sun way beyond the orbit of Neptune. Is there a mysterious “Planet Y” orbiting ...

Astronomers have identified a distant, slow-moving object in historical sky surveys that may represent a previously unknown ninth planet orbiting far beyond Neptune. The object, observed at an extreme ...

Astronomers studying the distant reaches of our Solar System have identified an unusual trans-Neptunian object (TNO) locked in a rare orbital configuration with Neptune. The object, discovered through ...