An object up to dozens of times the mass of Jupiter flying through our solar system may have disrupted planetary orbits.

But the formation process of multi-planet systems, like our own Solar System, is still poorly understood. The best example object to study multi-planet system formation is a young star known as ...

However, exactly how that happens for a multi-planet star system — like our solar system — is unknown. The paper, published today in The Astrophysical Journal Letters, details observations of ...

The orbits of the planets around the Sun have been the source for many a scientific debate. Their current orbital properties ...

The moderate tilts and slightly elongated paths of these planets — long considered a mystery — could be the result of a one-time cosmic flyby.

The solar system is approximately 4.6 billion years old. Astronomers believe that roughly 100 million years into its existence, the planets first began to form in a rotating, flat cloud of gas ...