Legend has it that somewhere beyond Neptune and Pluto, there is a ninth planet, with a mass that is five times greater than ...

Astronomers studying the outer solar system say the unusual alignment of distant objects points to the influence of Planet 9.

3I/ATLAS has now made its closest approach to the sun and Earth and is now heading back out toward the outer solar system. On ...

How common are Earth-like planets in the universe? When I started working on supernova explosions, I never imagined that my ...

Two cosmic collisions near the star Fomalhaut solve the mystery of a disappearing "planet" and show rare planetesimal crashes ...

One of the primary goals of the James Webb Space Telescope (JWST) is to detect atmospheres around exoplanets, to try to suss ...

Kuiper Belt clues, competing ideas, and how Rubin Observatory could finally reveal the hidden world soon by 2026.

Dec. 19 (UPI) -- Comet 3I/ATLAS passed its nearest point to Earth early Friday and approaching within 168 million miles.

This third confirmed interstellar comet to enter our neighborhood has captivated astronomers and sparked debate within the scientific community. NASA ...

In 2004, a bright point of light in the debris disk surrounding Fomalhaut was thought to be an exoplanet. But the spot ...

Oceans hiding within the crusts of distant moons are tantalizing targets for scientists looking for life beyond Earth ...

Today is one astronomers, stargazers and alien conspiracy theorists have been waiting for: interstellar comet 3I/ATLAS is as ...