Note that a diagonal line to the right indicates a beta decay, while a diagonal line to the left indicates an alpha decay. It is actually these decay series which account for certain radioactive elements that are found in nature that would not otherwise be expected. Once a specific radioactive decay series is known, and the half-life for a particular isotope is determined, scientists can use this information to calculate the age of a sample containing that isotope. As it turns out the answer may be found in cosmic ray particles. As mentioned earlier, cosmic ray particles are the particles that bombard the Earth from any location outside its atmosphere.
Scientists classify cosmic rays depending on their source.
The cosmic ray particles that are radioactive can become excellent indicators of their origin, their age, and the mechanism which brought them to our solar system. These atoms will not have the orbital electrons once they have been accelerated to speeds approaching the speed of light since the electrons will all have been stripped away. Once that occurs, these nuclei travel through space as a cosmic ray nucleus which is unable to decay. The amount of this isotope available in a given sample gives clues about the age and the origin of the sample. In the case of the cosmic ray clocks one of the interesting isotopes is beryllium-10.