Only eight of the bodies orbiting the Sun are now classed as planets. Students could explore the position of the sun at the centre of the solar system. Using differently-sized sports balls ...

astronomers found a planet orbiting the nearest star to Earth in this system, called Proxima Centauri. Graphic representation of the relative distances between the nearest stars and the Sun.

It actually follows its own tiny elliptical orbit around what is called the center of gravity (the barycenter) of the system, the sun and the orbiting planets. This barycenter is usually not equal ...