Re-Blogged From Space Weather
[Experiments at CERN are showing that Cosmic Rays are responsible for much rain droplet formation. Quieter Sun means less Solar Wind, which allows in more Cosmic Rays, which means more Clouds & Rain. Interesting stuff. -Bob]
Want to experience space weather? Just step onboard an airplane. At typical cruising altitudes, cosmic rays from deep space penetrate the hulls of commercial jetliners, dosing passengers with levels of radiation comparable to dental X-rays. To measure this radiation, Spaceweather.com has been flying cosmic ray sensors onboard airplanes over 5 continents. Our latest results show something interesting about the continental USA.
On April 9th and 11th we flew neutron bubble chambers from Portland, Oregon, to Washington DC and back again. In the photo, above, each bubble was created by a cosmic ray neutron. Why measure neutrons? Studies show that neutrons can be ten times more effective at causing biological damage compared to X-rays and gamma-rays in the same energy range. Neutrons are so effective, they are used for cancer therapy, killing tumors better than other forms of radiation.
During these flights, we measured more than 20 uGy of neutron radiation–the equivalent of two panoramic dental X-rays. That’s significant but not dangerous.
The interesting thing is how these values compare to other places we’ve flown. Our neutron chambers have traveled on 14 flights over North America, South America, Asia, Europe, and Africa, with typical altitudes near 35,000 feet. So far, neutron dose rates have been highest in one place: the continental USA (CONUS).
In this histogram, flights over CONUS are color-coded red. Other parts of the world are blue. The distribution’s red tail shows the tendency of US flights to “out-neutron” international flights. This may be a result of small-number statistics. If so, the anomaly could disappear when more data are added. Our neutron survey is continuing, so stay tuned.