Dallas shows an orrery – a mechanical model of the solar system. Before the 17th century most people believed in a geocentric model of the solar system. Dallas explains the geocentric model and ...

The way people think of the Solar System has changed many times throughout history. Before the development of the telescope, these ideas were based on what could be seen with the naked eye.

Images like that have captured imaginations during this surprisingly active solar cycle, and emphasized the importance of SDO in our solar early warning system. In a lot of ways, SDO has its roots ...

With a radius of 3,959 miles, Earth is the fifth largest planet in our solar system, and it's the only one known for sure to have liquid water on its surface. Earth is also unique in terms of ...