Define !
People!
100

Whats a system?

a set of collected parts

100

What is Keeplers big discovery 

planets move around the Sun in orbits shaped like ellipses.

200

Universe 

everything and everything in it

200

who discovered gravity 

Sir Isaac Newton

300

Geocentric theory 

The theory that states the planets and stars orbit earth

300

who discovered the geocentric theory 

Ptolemy

400

 heliocentric theory 

the theory that states the planets and stars revolve around the sun

400

who discovered the geocentric theory

Ptolemy

500

galaxys 

contains as, rock, dust and planets

500

who supported the heliocentric theory 

most all people from the past, the reason