Earliest to latest birth order is C, B, A.

C = Nicolaus Copernicus born in 1473;

B = Galileo Galilei born in1564;

A = Isaac Newton born in 1643.

Each made significant contributions to the science of astronomy. Copernicus rightly proposed the sun centered (heliocentric) model of the Solar system.

Galileo's contributions to observational astronomy include the telescopic confirmation of the phases of Venus, the discovery of the four largest satellites of Jupiter (named the Galilean moons in his honor), and the observation and analysis of sunspots. Galileo also worked in applied science and technology, inventing an improved military compass and other instruments.

Newton's "Principia" formulated the laws of motion and universal gravitation, which dominated scientists' view of the physical universe for the next three centuries.

More Info: www.astronomytrek.com