Astronomy Chapter 5

By making extensive observations of planetary motion, Tycho Brahe

provided only a lot of accurate data.

Tycho Brahe measured the positions of all the planets to an accuracy of

1/60 degree of arc.

Which of Kepler's Laws governs how a particular planet speeds up and slows down?

The Equal Area Law

In addition to being accurate, Tycho Brahe's observations focused on measuring the positions of the planets

all the time.

Kepler found that the orbit of Mars is best described as

an ellipse

Kepler's First Law of Planetary Motion is that the orbit of each planet is

an ellipse with the Sun at one focus.

Kepler was an early advocate of the Copernican Theory. When he applied it to Tycho's observations, it

failed but led to a better theory.

Tycho Brahe's work at Uraniborg was

funded by a large fraction of the national budget of Denmark.

One reason that the Copernican System failed to fit Tycho's observations was that

it used circular orbits instead of ellipses.

Tycho Brahe's main contribution to the understanding of planetary motion was to

make extensive observations.

Tycho Brahe's careful observations of the planets agreed with

none of these systems.

According to Kepler's Laws of Planetary Motion, as planets orbit the sun, they

speed up when closest to the Sun.