Do Androids Search for Cosmic Rays?

We always like citizen science projects, so we were very interested in DECO, the Distributed Electronic Cosmic-ray Observatory. That sounds like a physical location, but it is actually a network of cell phones that can detect cosmic rays using an ordinary Android phone’s camera sensor.

There may be some privacy concerns as the phone camera will take a picture and upload it every so often, and it probably also taxes the battery a bit. However, if you really want to do citizen science, maybe dedicate an old phone, put electrical tape over the lens and keep it plugged in. In fact, they encourage you to cover the lens to reduce background light and keep the phone plugged in.

According to the project website:

Cosmic rays are energetic subatomic particles produced by powerful cosmic accelerators, such as black holes and exploding stars. When they hit the top of the atmosphere, they produce showers of secondary particles, including electrons, photons, neutrinos, and muons. Many of these muons, which are similar to electrons but heavier, reach the ground at sea level and are a great tool for studying cosmic rays because they are easy to detect.

In practice, the app takes a photo every 1-2 seconds and looks for bright pixels. If it finds enough, the image becomes a candidate and receives further processing. Only a small number of frames are candidates and even fewer are actual events. They mention that it typically takes about 24 hours to get a few events on your phone. We aren’t sure how much data is sent to the server for processing and how much is done locally, but we suspect almost all the analysis is on the server. The app records your location but does degrade it somewhat for privacy.

You can see your results and the results of others on a public data page. There’s a map and you can narrow data by location, altitude, time, or even check in on a specific device or model.

Citizen and crowd-sourced science is all the rage lately, even NASA’s in. Citizen science even located a lost moon lander.