Cosmic Ray Observatory Project

The Cosmic Ray Observatory Project links secondary schools across Nebraska with professional astronomers and physicists to study cosmic rays. The students build networked cosmic ray detectors that they mount on the roofs of their schools. The data flow into the project’s archives, letting professional astronomers study high-energy cosmic rays.

The fusion reactions inside stars can only go so far. Iron is the heaviest element that forms during normal stellar fusion. The intense pressures as a star’s core collapses are so powerful that they form all of the other elements. Then the star explodes. Nuclei of hydrogen, helium, iron, lead, uranium and all of the other elements blast away from the dying star. Some of these nuclei reach near-light speeds and become what we call galactic cosmic rays. They follow twisted paths through the Milky Way as magnetic field push and pull the charged nuclei. Thousands or millions of years later one of these nuclei reaches our Solar System.

And then things get interesting.

The combination of large mass and extremely high speeds make galactic cosmic ray particles extremely energetic. A single particle can have millions of times more energy than the particles whipping through Earth-based particle accelerators such as the Large Hadron Collider. When one of these particles strikes an atom in the upper atmosphere, the particle and atom destroy each other and release more subatomic particles. These particles collide with other atoms, producing more particles. A chain reaction of collisions sends a shower of subatomic particles cascading to Earth.

By the time it reaches Earth, the shower of particles has spread out over a large area. Like forensic analysts at a crime scene, scientists must reconstruct the original collision by measuring the subatomic debris raining down on the surface. That’s where the scientists collide with another fundamental force - economics. Installing a network of sensors across hundreds or thousands of square kilometers is expensive. You have to lease the land, provide electricity, and pay for communications. Unless, of course, you don’t.

That’s where the Cosmic Ray Observatory Project comes in. Teachers work with researchers at the University of Nebraska, Lincoln’s Physics & Astronomy Department to install inexpensive cosmic ray detectors on the roofs of their schools. In exchange for free hosting, the schools’ students get to take part in a real high-energy physics research project. Students analyze data collected by “their” sensors, compare them to data from other schools, and reach their own conclusions. Workshops and video conferences let the students take part in the state-wide project. The professional scientists running the project “pay forward” by supporting the next generation of scientists while getting an inexpensive cosmic ray observatory that lets the scientists do their own peer-reviewed research.

Crop began in 1999 and is the longest-lived educational cosmic ray observatory in the United States. It recently secured a new half-million dollar grant from the National Science Foundation. This grant will let the program expand beyond the urban centers of Lincoln and Omaha. Expanding the network’s footprint with more widely-separated rural schools lets the students and scientists study even larger cosmic ray bursts.