TRI-CITIES, Wash., - A new educational project is set to transform the trails along the Columbia River into a scale model of ...

Scientists are refining galactic motion models to predict whether the solar system might enter another dense region in the ...

This model of solar system formation is known as the nebular hypothesis. The solar system is structured in a roughly flat plane called the ecliptic, with most planets orbiting the sun in the same ...

and proved the heliocentric model (Mars’ retrograde motion). Students could calculate the distances and sizes of the planets in the solar system based on the Sun being the size of a football.

An Egyptian astronomer called Ptolemy (AD100-168) described one of the earliest ideas for how the Solar System is structured. Ptolemy’s model and many earlier ideas of the Solar System had the ...