He made a powerful telescope
planetary motion laws
Galileo
The laws of planetary motion are attributed to Kepler.
Direct motion is the motion of planetary body in a direction similar to that of other bodies within its system, and is sometimes called prograde motion. Retrograde motionis motion in the opposite direction.
3 laws' of planetary motion
Keplar figured out the laws of planetary motion using Tycho Brahe's data.
They all obey Kepler's 3 laws of planetary motion.
Johannes KeplerHis first two laws were published in Astronomia Nova(The New Astronomy) in 1609. His Third Law was published in 1618, in book five of his Harmonices Mundi (The Harmonies of the World.)
There are numerous theories of planetary motion. Ptolemaeus (earth in the centre), Copernicus (the sun in the centre, planets orbit around it), Kepler (planet orbits are ellipses) all wrote such theories.
They are in the shape of an ellipse.
The Greek astronomer's explanation for the celestial spheres did not encompass the phenomenon of retrograde motion. The retrograde motion is the apparent motion of a planet to move in the opposite direction from the surrounding planetary bodies in the same system.
to the world