What data did Tycho Brahe collect that was useful to Johannes ...

[lilldybug07]

What data did Tycho Brahe collect that was useful to Johannes Kepler in his quest to describe planetary motion?
 
  What will be an ideal response?

Question 2

What major change did Copernicus make in the Ptolemaic system? Why was this change philosophically different?
 
  What will be an ideal response?

[Sarahjh]

Answer to Question 1

Tycho Brahe tried to collect measurements of stellar parallax to disprove Copernicus's heliocentric theory. Kepler later used these measurements to prove the Copernican model correct.

Answer to Question 2

Copernicus changed the view of the solar system from a geocentric one to a heliocentric one, where the Sun became the center around which all planetary bodies orbited. This change was philosophically different in that Copernicus held the Sun as a great monumental illuminating body that should, of course, be at the center.

[lilldybug07]

Excellent

[shewald78]

Thanks for the timely response, appreciate it