Add Yahoo as a preferred source to see more of our stories on Google. Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky ...

Mercury, Venus, Earth, Mars...When you hear the names in order, some of you might think, "I learned that in school."But doesn't the Moon belong to that group?Does asteroid just mean a small ...

When 'Oumuamua traversed our solar system in 2017 it was the first confirmed Interstellar Object (ISO) to do so. Then in 2019, Comet 2l/Borisov did the same thing. These are the only two confirmed ...

Learn how Pluto nearly kept its planet status in a proposed 12-planet Solar System as its demotion marks its 20th anniversary. Eight days before Pluto lost its planetary status, it appeared ready to ...