What role did astronomy play for Isaac Newton? He was a good friend with Edmond Halley the astronomer. Kepler's laws were obviously the foundation for his physics. And he revolutionized optics too, but did he make any systematical astronomical observations, as in for example checking the planet's movements or mapping the surface of the Moon? He isn't famous as an astronomer, but that is maybe just because it is overshadowed by his other accomplishments.
Newton's telescope (replica).