So it seems a bit rough that we blame Mercury for all our problems three to four times a year when it’s in retrograde. But what does it mean when we say Mercury is “in retrograde”? Let’s use my dog Astro to help explain what’s happening when we see a planet in retrograde. This is what happens when we look up at the sky and see one of the outer planets in retrograde. Astronomers like Apollonius around 300 BCE saw the planets going backwards, and explained this by adding more circles called epicycles.

Source: The Hindu May 09, 2023 13:33 UTC