Add Yahoo as a preferred source to see more of our stories on Google. (Ianm35/iStock/Getty Images Plus) The Solar System is one of the comforting constants of human existence. No matter what else we ...

Trans-Neptunian objects (TNO) are some of our solar system's lesser-known objects. They number in the thousands, and they get their name from their orbits. These dwarf planets orbit the sun at a ...

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 ...

Earth and Mars were formed from material that largely originated in the inner solar system; only a few percent of the building blocks of these two planets originated beyond Jupiter's orbit. A group of ...