Spencer Axani, a physics professor at the University of Delaware, has invented CosmicWatch, a portable and affordable muon detector aimed at making cosmic-ray research accessible for both educational purposes and scientific endeavors.. This innovative device enables students and researchers to detect and study muons, which are subatomic particles originating from outer space that are crucial for understanding extreme astrophysical phenomena such as supernovae, gamma-ray bursts, and blazars.. CosmicWatch, approximately the size of an animal cracker box, is constructed from electronic components costing around $100, making it a cost-effective tool for scientific exploration.. The detector lights up and counts each muon it registers.. Axani initially developed CosmicWatch in 2017 as a graduate student at MIT with the goal of creating a small, low-power muon detector for the IceCube observatory in Antarctica, which primarily tracks neutrinos.. The project evolved into an educational outreach program when Axani recognized the potential for a portable, inexpensive detector.. After joining the University of Delaware faculty in 2022, Axani continued to refine CosmicWatch, releasing its third version.. Recent upgrades, detailed in the Journal of Instrumentation, enhance the device's ability to monitor its local environment, withstand high radiation levels, and accelerate data collection.. CosmicWatch is now being utilized in international astrophysics experiments and is incorporated into high school and college classrooms across the United States, introducing a new generation to particle physics.. The detector's ability to pass through solid objects without damage also makes it useful for studying phenomena on Earth..