Question

Historical models of the solar system included a blank model or earth-centered universe and a blank model or sun-centered universe.

1.Geocentric 
2.Heliocentric 
3.Nebular

Answer 1

For "Earth-centered" it was " Geocentric Theory proposed by greeks under the guidance of Ptolemy and "Sun-centered" was Heliocentric theory proposed by Nicolas Copernicus in 16th century A.D.

In short, Your Answers are: 1st blank - Geo-Centric Theory
2nd blank - Heliocentric Theory

Hope this helps!

Answer 2

Geocentric for the Earth centered one

Heliocentric for the Sun centered one