One of the greatest mysteries in astrophysics these days is a tiny subatomic particle called a neutrino, so small that it passes through matter—the atmosphere, our bodies, the very Earth—without detection. [23] Physicists from the Cluster of Excellence PRISMA+ at Johannes Gutenberg University Mainz (JGU) play a leading role in a new study that indicates that the puzzle of neutrino mass ordering may finally be solved in the next few years. [22] If it turns out that neutrinos and antineutrinos oscillate in a different way from one another, this may partially account for the present-day matter–antimatter imbalance. [21] Studying this really interesting particle that's all around us, and yet is so hard to measure, that could hold the key to understanding why we're here at all, is exciting—and I get to do this for a living," says Mauger. [20]