The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

Simpson and Chen ran mathematical models looking at how differently sized Earth-like worlds would have affected the rest of ...

Ever since Isaac Newton famously talked about gravity, its dominance as a force in our solar system has been well known. It's ...

Analysis of debris from the nearly 5 billion-year-old asteroid Bennu suggests the building blocks of DNA and RNA were present ...

The enormous visitor to our solar system may have been about 8 times the mass of Jupiter, and come nearly as close to the sun ...