Astronomers are closing in on one of the most tantalizing possibilities in planetary science, evidence that a previously unknown world may be lurking in the outer reaches of the solar system. The ...

NASA is inviting the public to join 36 citizen science projects. Volunteers can help with discoveries from asteroids to Martian clouds. To join, email do-nasa-science-join@lists.nasa.gov with ...

The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have dubbed ...