'planetary motion' is a correct and usable phrase in written English.
Example: Scientists have studied the patterns of planetary motion for centuries.
It guided Johannes Kepler (1571 1630) to his discovery of the laws of planetary motion.
With Kala-kriya Aryabhata turned to astronomy in particular, treating planetary motion along the ecliptic.
Against his will he was forced to reexamine the fundamentals of planetary motion.
Kepler later used Brahe's measurements to come up with the laws of planetary motion.
Although the Ptolemaic system successfully accounted for planetary motion, Ptolemy's equant point was controversial.
These models were well adapted for explaining other phenomena of planetary motion.
An Arab astronomer, Ibn al-Shatir, spelled out the theory of planetary motion 150 years before Copernicus.
"When Kepler found the laws that govern planetary motion, he didn't get the laws exactly right," West says.
His philosophy enshrined number as the unifying concept necessary for understanding everything from planetary motion to musical harmony.
This led to the first two of Kepler's laws of planetary motion, published in Astronomia Nova (New Astronomy, 1609).
Eudoxus of Cnidus constructed the first Greek theory of planetary motion of which any details are known.
