image: Top view of the double wavelength Mach-Zehnder-type laser interferometer with the nucleation chamber. This material relates to a paper that appeared in the Jan, 18, 2017, issue of Science Advances, published by AAAS. The paper, by Y. Kimura at Hokkaido University in Sapporo, Japan, and colleagues was titled, 'Pure iron grains are rare in the universe.' view more
Credit: [Credit: Yuki Kimura]