Which way is ‘down’ has a different answer depending on where you are on Earth, in the solar system, in our galaxy and beyond ...

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to [email protected]. Are planets in the solar system that are closer ...

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 ...