In 1987 diamond grains and silicon carbide grains were found to exist abundantly in those same acid-insoluble residues and also to contain large concentrations of noble gases. Significant isotopic anomalies were in turn measured by improvements in secondary ion mass spectrometry (SIMS) within the structural chemical elements of these grains. Improved SIMS experiments showed that the silicon isotopes within each SiC grain did not have solar isotopic ratios but rather those expected in certain red-giant stars. The finding of stardust is therefore dated 1987. To measure the isotopic abundance ratios of the structural elements (e.g. silicon in an SiC grain) in microscopic stardust grains had required two difficult technological and scientific steps: 1) locating micron-sized stardust grains within the meteorite's overwhelming mass; 2) development of SIMS technology to a sufficiently high level to measure isotopic abundance ratios within micron-sized grains. Ernst Zinner became an important leader in SIMS applications to microscopic grains.