This article was originally published at The Conversation. The publication contributed the article to Space.com's Expert Voices: Op-Ed & Insights. The size of the solar system is defined by the volume ...

Watch this video to find out more about the Earth, planets in our Solar System and other planets far off in outer space. From up here on the International Space Station I get a great view of Earth.

The size of the solar system is defined by the volume of space over which the Sun’s influence exceeds those of other nearby stars in the Milky Way galaxy. This influence derives from two fundamental ...