Heidelberg has been a home for astronomy innovation for centuries. In 1609 Kepler's Astronomia Nova was printed here. Heidelberg also saw the birth of astrophysics, which can be marked by Kirchhoff's amd Bunsen's use of their new spectral analysis to determine the composition of the sun for the first time in 1859. Germany's first mountain observatory was erected on Königsstuhl in 1898. Today, thanks to the contributions of six science institutes, Heidelberg is an internationally renowned center of astrophysics.