The War with Mars
For thousands of years, people struggled to understand why the planets moved as they did against the back drop of stars. It was a small number of individuals whose collective works came together to finally unravel their mystery. Of all of these one stands out. Johannes Kepler’s fight to unlock the secrets of one planet, a battle that he himself termed his “war with Mars”, laid the foundations of modern astronomy and led to our conquest of space.
Podcast
(created by Google NotebookLM)
The Europa Clipper space mission relies on an accurate knowledge of planet positions, Earth, Mars and Jupiter, as it requires gravity assist to finally reach Jupiter’s moon Europa in 2030.
The ancient view was that planets moved on circles. To predict planet orbits, more and more complex circles needed to be added.
A reproduction of Newton’s diagram explaining orbital motion - a ball launched from the mountain falls towards the Earth but the ground also moves away due to Earth's spherical nature. Eventually the rate at which the ground curves away is equal to the rate at which the ball falls leaving it in orbit.