How many cosmic rays strike the ground each second?
The rate of cosmic rays reaching us falls off rapidly as the cosmic ray energy increases. For 1 GeV GeV: 1 giga electron volt (GeV) = 1 x 109 eV’);”> –> 9 eV’, TITLE, ‘GeV:’, OFFSETX, 360)” onmouseout=”UnTip()”> particles, the rate is about 10,000 per square meter per second. At 1000 GeV (or 1012 eV), the rate is only 1 particle per square meter per second. The rate starts to decrease even more rapidly around 1016 eV, where there are only a few particles per square meter per year. The highest energy particles, above 1019 eV, arrive only at a rate of about one particle per square kilometer per year.
