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 ...

At the beginning of the exoplanet age, the goals were fairly simple. The first was to find as many of them as possible to ...

As far as we know Neptune is the furthest full-size planet in our Solar System, orbiting the Sun some 2.69 billion miles away ...

Planetary rings explained: composition, formation theories, and a comparison of Saturn, Jupiter, Uranus, and Neptune’s rings.

CAPE CANAVERAL, Fla. - Chalk up one more moon for Neptune. NASA announced the discovery of Neptune's 14th moon Monday. The Hubble Space Telescope captured the moon as a white dot in photos of Neptune ...

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 ...