Kosmisk stråling
Gul - solar kosmisk stråling.
Blålig, cyan – GCR, galaktisk kosmisk stråling – fra mælkevejen.
Lilla, magenta – ECR (inkl. UHECR og EECR) – intergalaktisk kosmisk stråling – fra andre galakser.
Kosmiske stråler er subatomare partikler eller atomer med oprindelse udenfor Jordens atmosfære, som har en kinetisk energi fra nogle få milliarder eV til mere end 1020 eV. Kosmiske strålers subatomare partikler kan være elektroner, protoner, neutroner og ioniserede atomer. De ioniserede atomer er fra en stor del af det periodiske system – helt op til uran. [2] [3]
En lille del, ca. 0,1% af de kosmiske stråler, er fotoner i form af gammastråler. [2]
I 1993 observerede man i Utah den mest energirige kosmiske stråle partikel på 3*1020 eV. [4]
Når jordens atmosfære rammes af en partikel eller gammafotoner vil jordens magnetfelt og atmosfærens gas omdanne og bremse en kosmisk stråle. [5]
Flere forskere mener at kosmisk stråling har direkte indvirkning på den globale opvarmning, i og med at ændringer i klodens temperatur følger ændringer i den kosmiske stråling over de sidste mange år. Faktisk menes dette at have langt større indvirkning end drivhusgasser.[kilde mangler]
Det formodes at hovedkilden til kosmiske stråler er supernovaeksplosioner. [3]
Kilder/referencer
- ^ macalester.edu: An Introduction to Cosmic Rays Citat: "...They are then picked up by the solar wind and carried back to the outer heliosphere. Lastly, they are somehow accelerated, e.g. by the solar wind termination shock, and drift into the inner heliosphere as cosmic rays..."
- ^ a b University of Leeds: What are cosmic rays? Citat: "...vast majority of cosmic rays are protons, although other heavier atomic nuclei are also present, extending all the way up to uranium nuclei...A small fraction (0.1%) of cosmic rays are photons (in the form of gamma-rays)..."
- ^ a b 23 April, 2002, BBC News, Cosmic ray mystery 'solved' Citat: "...Cosmic rays are bits of matter: protons, electrons, and atomic nuclei which have been stripped of their electrons. Although supernovae, gigantic exploding stars, have long been suspected as the source of most rays, the origin of the highest-energy rays has been more difficult to tie down..."For the first time, we see the hint of a possible connection between the arrival directions of ultra-high energy cosmic rays and locations on the sky of nearby dormant galaxies hosting supermassive black holes," said Princeton's Dr Diego Torres..."
- ^ University of Leeds: The Very Highest Energy Cosmic Rays Citat: "...In 1993 the "Fly's Eye" experiment in Utah detected a cosmic ray with an energy of 3x10^20 eV. So far this is the highest energy particle ever detected...", hocedadresse: University of Leeds: What are cosmic rays?
- ^ Particle Physics & Astronomy Research Council (2004, November 5). Possible Origin Of Cosmic Rays Revealed With Gamma Rays. ScienceDaily Citat: "...luckily for life on Earth, gamma rays from objects in outer space are stopped by the atmosphere..."
- Chandra X-ray Center (2005, September 23). Tycho's Remnant Provides Shocking Evidence For Cosmic Rays. ScienceDaily Citat: "...some modern ideas of the aftermath of supernova explosions may have to be revised. The report by Hughes and colleagues demonstrates that the shock wave produced by the explosive disruption of the star behaves in a way that cannot be explained by the standard theory..."
Se også
- Polarlys (nordlys og sydlys)
Eksterne henvisninger
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Wikimedia Commons har medier relateret til: |
- Google: Cosmic Rays
- Cosmic Rays
- Pierre Auger Observatory: An International Facility to Study the Highest Energy Cosmic Rays
- Northeastern University: Cosmic ray papers
- 31 October, 2003, BBCNews: Solar storm surge 'not over yet' Citat: "...aircraft traversing the north Atlantic were confined to a narrow corridor to minimise radiation exposure..."
- Los Alamos National Laboratory (2004, May 5). Scientists Announce Cosmic Ray Theory Breakthrough. ScienceDaily Citat: "...The theory could be the basis for a whole new understanding of the ways in which cosmic rays -- and their signature radio waves -- propagate and travel through intergalactic space..."