this page honors Nicholas Copernicus (1473-1543)
In his work, Copernicus used observations made by Ptolemy and other ancient astronomers as he prepared the data tables and the detailed geometric proofs he used to support his ideas. In addition, he followed Ptolemy's advice for "posterity to seek finer precision" in the effort to learn about the nature of the universe. To this end, Copernicus built a piece of equipment similar to Ptolemy's astrolabe, a kind of "parallactic instrument" to make his own observations.
While Copernicus was working out the details of the orbit of Jupiter, he made observations "with the greatest care in [determining the] oppositions of Jupiter." He also made measurements to define "the other phenomena connected with Jupiter, namely, its parallax…."
This parallactic instrument was later acquired by Tycho Brahe, who was so delighted to own it that he wrote a poem about it in epic meter. Alas, it shared the fate of the other instruments in Tycho's collection — they were destroyed during the Thirty Years' War.