Cosmic rays are very high energy particles that penetrate Earth atmosphere and sometimes even reach the surface. High energy means much, much higher than for example we are able to generate in the Large Hadron Collider. Most energetic cosmic rays particles observerd had energy 40 million times larger than particles accelerated in the LHC. These particles are mainly originated outside the Solar System and even outside the Milky Way. Every few moments at least one of this particles goes through your body. They have sufficient energy to alter the state of electronics integrated circuits causing errors to occur such as corrupted data in memory or incorrect performance of CPU.
They also affect day by day astronomers work of course causing different artifacts on long exposured CCD sensors. Here is the dark calibration frame taken with Atik 383L with exposition time of 20 minutes. The sensor has not been actually exposed to any light – it was tightly covered with the metal cap. You can see (when enlarge) there some hot pixels and some thermal noise (sensor has been cooled to -20C). And also during these 20 minutes some cosmic rays hit the sensor surface at different angles and caused some artifacts.
In the next picture some of this artifacts have been cut out and enlarged. You can see how different they are. You can also try to imagine what happened during this exposition, when those cosmic wanderers eventually hit the sensor surface after the million years of traveling across the space…
The origin of cosmic rays is still a little bit mysteriuos. It is believed that some of them are created during supernovae and other big stars explosions, but active galactic nuclei probably also produce cosmic rays.
Clear skies! (even under cloudy sky cosmic ray can hit you 🙂 )