Answer:
1. Ptolemy.
2. Nicolaus Copernicus.
3. Tycho Brahe
4. Galileo Galilei
5. Isaac Newton
6. William Herschel
7. Johann Galle
8. Clyde Tombaugh
9. Albert Einstein.
10. Edwin Hubble
11. Karl Jansky.
12. Grote Weber.
Explanation:
1. Ptolemy: said sun revolved around earth.
2. Nicolaus Copernicus: aid earth revolved around sun.
3. Tycho Brahe: analyzed motions of planets.
4. Galileo Galilei: first used refracting telescope for astronomy.
5. Isaac Newton: invented reflecting telescope.
6. William Herschel: discovered the planet Uranus.
7. Johann Galle: discovered the planet Neptune.
8. Clyde Tombaugh: discovered the dwarf planet Pluto.
9. Albert Einstein: developed special and general theories of relativity.
10. Edwin Hubble: demonstrated that universe is expanding.
11. Karl Jansky: discovered radio waves from the center of the Milky Way.
12. Grote Weber: an amateur astronomer who built the first radio telescope.