 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
Superflares Could Kill Unprotected Astronauts
London (SPX) Mar 17, 2005 A study of the most powerful solar flare over the last 500 years suggests a similar future one would be strong enough to kill astronauts in a poorly shielded spacecraft, reports New Scientist. According to the British science weekly, astronauts on route to Mars might be at risk unless their craft is made of the right materials. Solar flares send high-energy protons streaming through the solar system, and the radiation can be intense enough to be a threat to the health of astronauts. And compared to the Apollo missions to the moon that took only a few day, the many months it will take to get to Mars makes the issue critical to ensuring crew safety. And just this past January, the current space station crew had to take shelter in the bulkier Russian side of the station during a powerful series of flares. Scientists have only been able to directly measure the radiation from solar eruptions for the past four decades. To this end, Lawrence Townsend of the University of Tennessee in Knoxville and his colleagues have calculated the radiation effects of the most powerful solar flare ever recorded, based on evidence that the flare left behind in Greenland's ice nearly 150 years ago. By chance this flare was seen by a British astronomer in September 1859, and the radiation from this flare created nitrates and beryllium-10 in Earth's upper atmosphere. These ended up frozen into Greenland ice. The amount of nitrates found in ice cores collected from Greenland suggests that Earth was hit by about 20 billion high-energy protons per square centimeter, more than in any other event of the past 500 years. And the beryllium reveals that the energy spectrum of these protons was roughly equivalent to that of a flare recorded in August 1972. According to New Scientist, Townsend's team have now used this information to calculate the radiation levels astronauts would be exposed to from super flares as determined by different grades of shielding. They found that astronauts behind only a few centimeters of aluminum - the shielding you'd find in the average spacecraft- would suffer a dose that could cause acute radiation sickness and possibly even death. "Aluminum is not a good radiation shield," says Townsend. "We are looking at alternative materials, such as polyethylene and carbon foams impregnated with hydrogen. A worst-case event would probably be survivable if you use some other material than aluminum." This report is based on an article that will appear in the March 19 issue of New Scientist. Community Email This Article Comment On This Article Related Links SpaceDaily Search SpaceDaily Subscribe To SpaceDaily Express Space Technology News - Applications and Research
TeleRay Mobile Sat TV Antenna For Japan Auto Market
Las Vegas CA (SPX) Jan 5, 2006RaySat has introduced TeleRay, the world's smallest satellite TV vehicle antenna, into the domestic Japanese automotive market. |
|
|
| The content herein, unless otherwise known to be public domain, are Copyright 1995-2006 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA PortalReports are copyright European Space Agency. All NASA sourced material is public domain. Additionalcopyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement |
