USA Today

Mercury is retrograde. Several planets appear to 'step back,' and here's what that means.

Mercury will retrograde from Dec. 13 through Jan. 2 in the last of four times it appears to move backward in the sky this year. Every planet has in our solar system has retrograded for at least part ...
USA Today

Mercury isn't the only planet that retrogrades. Every planetary 'step back' and what it means.

Mercury will retrograde, or appear to be moving backward in the sky, from August 23 through September 15. It's the third of four times Mercury will be moving in retrograde this year. Mercury isn't the ...
The Conversation

People are complaining about Mercury in retrograde. But what does it actually mean?

Laura Nicole Driessen is part of MeerTRAP, which is supported by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No ...
insider.si.edu

The ballet of the planets : on the mathematical elegance of planetary motion / Donald C. Benson

The survival of the valid. Peer review ; The scientific method -- Birth. The bowl of night. The two-sphere universe ; Coordinate systems l The sun -- Epicycles and relative motion. A mechanical ...