JUNE 28, 2000
Using a focused, monochromatic beam of high-photon-energy x-rays from the Synchrotron Radiation Instrumentation Collaborative Access Team beamline 1-BM at the Advanced Photon Source, researchers performed metallurgical analyses on two astrolabes: M-33a (Adler Planetarium, from the Mensing Collection), and DW0595 (Harvard University, from the David P. Wheatland Collection). These instruments are both signed "Ioannes Bos, 24 March 1597." Results indicate that the composition and microstructure of the main components of M-33a are consistent with the 1597 date, while those of DW0595 reveal a much more recent origin.