Cosmic-Ray Extremely Distributed Observatory (CREDO) is an expanding world wide network of cosmic ray detectors, utilising both professional observatories and private mobile devices such as smartphones. The main objective of CREDO is to look for cosmic ray events which are extended in both time and space and thus beyond the abilities of localised detectors to identify. Such events have interdisciplinary applications in areas such as geophysics and space weather as well as astrophysics. The involvement of non-professional science enthusiasts in CREDO is enhanced by competitions for schools, various conferences and workshops where citizen scientists are invited to particle detection using a smartphone application, explore the cosmic ray events detected around the world.

CREDO & Citizen science

An important element in the project is to involve as many non-scientists as possible at different levels. In addition to detecting cosmic-rays with our application, we enable anyone interested to analyse and classify detections according to their own ideas or in collaboration with scientists.

CREDO & Popularisation

In an effort to increase the level of knowledge about the Cosmic Rays, we organise various conferences, lectures and demonstrations allowing even the youngest to get acquainted with this subject. In addition, in order to increase the interest among the youngest, we organise for schools a competition "Particle Hunters" consisting in a team detection of particles using the CREDO application.

CREDO Detector

To make it possible for anyone to detect cosmic ray particles without spending a lot of money on a detector, the CREDO project has created the "CREDO Detector" (link  application that runs on Android 4+ smartphones. Every user can see his detections on (link and download them for his own analysis after contacting us by email at contact[at]

And for those who have a MAC (Iphone) thanks to the cooperation of many institutions the "Cosmic Ray - Detect Radiation" (link ) application is available. We are currently working on merging the two databases of detections in order to allow everyone to access data from both databases at the same time.


CREDO Detections

The variety of particle images we detect is extremely large. We can try to classify them into only x classes e.g. 4 such as







and artifacts (bad detection, reason: 95% of the time the device's camera is badly covered or a light source is nearby).


However, there are many examples which do not fit 100% into a any class such as



CREDO is global

The CREDO project is comprised many institutions (about 50 from different countries) from all continents. Thanks to the great interest in the project, our application is used all over the world.


Status: beginning of June 2021