Ptolemy didn't actually discover the solar system. He developed a model of the universe that was used for over 1400 years, but it was geocentric, meaning it put the Earth at the center. This is different from our modern understanding of the solar system, which is heliocentric, meaning it puts the Sun at the center.

Here's a breakdown of Ptolemy's contributions and the context:

* Ptolemy was an astronomer, mathematician, and geographer who lived in Roman Egypt around 100-170 AD. He wrote a book called the *Almagest*, which was a compilation of astronomical knowledge from earlier Greek philosophers.

* Ptolemy's model explained the apparent motion of the planets using a system of circles called epicycles. This model worked surprisingly well at predicting planetary positions, which is why it remained the dominant model for so long.

* However, Ptolemy's model was based on the assumption that the Earth was stationary at the center of the universe. This assumption was later proven incorrect by Nicolaus Copernicus in the 16th century, who proposed the heliocentric model.

So, while Ptolemy made significant contributions to astronomy, he didn't discover the solar system as we understand it today. He developed a geocentric model, which was a valuable tool for its time but ultimately incorrect.