# Johannes Kepler (Dec 27, 1571 - Nov 15, 1630)

Timeline created by MooreKylie
• # First Cosmological Model

Kepler discovered a new mathematical model for our solar system in his Copernican theory. He determined that there were only six planets instead of seven.
• # First Law of Planetary Motion

The center of the ellipse is only the focus. However before Kepler discovered this, it was believed that the Sun was the center of the ellipse. Another key part of this law is that the distance between the Earth and Sun is ever changing as Earth rotates around its orbit.
• # Second Law of Planetary Motion

In this law it is explained how a planet is always in an elliptical motion. As this planet nears the Sun, it will pick up speed as it moves around its orbit. However, whenever the planet is at the furthest point away from the sun, it is on a slower elliptical pattern. The point at which the planet is nearest to the Sun is called Perihelion. The point at which the planet is furthest from the Sun on its elliptical pattern is Aphelion.
• # Third Law of Planetary Motion

This law took quite a bit longer to establish aside from the first two laws. Kepler created an equation to determine how long it would take a planet to orbit the Sun is. For example, since Mercury is the closest planet to the Sun, it only takes 88 days to orbit the Sun.