Galactic cosmic ray
 |
This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (April 2011) |
Galactic cosmic rays (GCRs) are cosmic rays that have their origin inside our Galaxy. GCRs are high-energy charged particles, and are usually protons, electrons, and fully ionized nuclei of light elements. They are a strong source for cosmic ray spallation in the atmosphere of the Earth.[not verified in body]
Contents |
[edit] Origin
The magnetic fields of the Earth, the sun, and the galaxy itself bend the paths of the galactic cosmic rays.[citation needed]
Some of the isotopes have half-lives that are comparable to the time interval since their formation, and isotopic ratios can therefore carry some information about the amount of time that has passed since they were formed. In a few cases, there are isotopes are unstable with respect to electron capture, but because they are fully stripped, they have not decayed in flight.[citation needed]
[edit] Observation
Most galactic cosmic rays have energies too low to penetrate the Earth's atmosphere, and the radii of their helical trajectories in the Earth's magnetic field tends to channel them to the poles. When they strike the atmosphere, they can create large showers of secondary particles that are detected on Earth's surface.
[edit] As a radiation hazard
Galactic cosmic rays are one of the most important barriers standing in the way of plans for interplanetary travel by crewed spacecraft.
[edit] References
 |
This article includes a list of references, related reading or external links, but its sources remain unclear because it lacks inline citations. Please improve this article by introducing more precise citations. (October 2009) |
