Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A cloud of collapsing gas created our Sun, the first thing to ...

There, it was decided that in order for an object to be considered a planet in our solar system, it must ... For Pluto and the 8 planets, this process begins with clouds of gas and dust in ...

But that includes exoplanets, alien worlds that orbit alien suns. Only eight planets call our solar system home. Or there might still be nine if some astronomers are correct about an as-yet ...

(The Conversation is an independent and nonprofit source of news, analysis and commentary from academic experts.) Are planets in the solar system that are closer to the Sun older than the ones ...