Have you ever wanted to detect the amount of interstellar cosmic radiation hitting the earth? It’s probably not top of mind for most people but a professor of physics from the University of Wisconsin thought that would be cool so he created an app to do just that!

Cosmic rays are high-energy subatomic particles that travel at tremendous speeds across the galaxy. When they hit the Earth’s atmosphere, they collide with oxygen and nitrogen and breakdown into things like electrons, neutrons, muons and x-rays. They break down even further until they reach the ground where the amount and intensity of the cosmic ray can actually be measured.



The new smartphone app turns your phone into a high-energy particle detector in ways similar to the way instruments found in high-tech observatories and laboratories work. To work, the camera, using a CMOS lens, detects the muons. When the muon strikes the pixels in a CMOS  smartphone camera, it causes an electrical current flow that can be captured, stored, and analyzed within the app.

The DECO app, once downloaded, works very easily. To get started the smartphone camera needs to be covered with a piece of duct tape to keep light and other visible radiation from reaching the lens. With the phone facing screen up, you can leave it nearly anywhere, even in a desk drawer – it will still capture the data.

The app is programmed to take an image every few seconds, and then analyze that image. If a sufficient number of pixels are energized on the CMOS IC, the image gets recorded as an event. As a result, both cosmic rays and radioactivity detected by the phone camera can be recorded.

While it isn’t likely that smartphones are going to replace high tech equipment, it is believed that this app may grab the interest of scientific minded people. Students and the public interested in the activity of the solar system may find they are able to observe things they don’t ordinarily get a chance to see.