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Cosmic-ray observatory
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<h2 id="history">History</h2> <p>"In 1952, a simple and audacious experiment allowed the first observation of <a href="/facts/Cherenkov_radiation/lSPJAC3U">Cherenkov light</a> produced by cosmic rays passing through the atmosphere, giving birth to a new field of astronomy".<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a> This work,<a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a> involving minimal instrument expense (a dustbin, a war-surplus parabolic mirror, and a 5 cm diameter photomultiplier tube), and based on a suggestion by Patrick Blackett, led ultimately to the current international multibillion-dollar investment in gamma ray astronomy. </p><p>The <a href="/facts/Explorer_1/m4jWb1A0">Explorer 1</a> satellite launched in 1958 subsequently measured cosmic rays.<a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a> Anton 314 omnidirectional <a href="/facts/Geiger-M%25C3%25BCller_tube/RK67ylYg">Geiger-Müller tube</a>, designed by <a href="/facts/George_H._Ludwig/bqd4tkgH">George H. Ludwig</a> of the <a href="/facts/State_University_of_Iowa/pBzJ1vxe">State University of Iowa</a> Cosmic Ray Laboratory, detected <a href="/facts/Cosmic_ray/uxCVdTKd">cosmic rays</a>. It could detect <a href="/facts/Proton/clCjepXP">protons</a> with energy over 30 <a href="/facts/Electronvolt/YMT1fqX9">MeV</a> and <a href="/facts/Electron/L0KBo5cW">electrons</a> with energy over 3 MeV. Most of the time the instrument was <a href="/facts/Saturated_absorption/FfIq3Qks">saturated</a>;<a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a> </p><p>Sometimes the instrumentation would report the expected cosmic ray count (approximately thirty counts per second) but sometimes it would show a peculiar zero counts per second. The University of Iowa (under Van Allen) noted that all of the zero counts per second reports were from an altitude of 2,000+ km (1,250+ miles) over South America, while passes at 500 km (310 mi) would show the expected level of cosmic rays. This is called the <a href="/facts/South_Atlantic_Anomaly/j5lUGjh3">South Atlantic Anomaly</a>. Later, after Explorer 3, it was concluded that the original Geiger counter had been overwhelmed ("saturated") by strong radiation coming from a belt of charged particles trapped in space by the Earth's magnetic field. This belt of charged particles is now known as the <a href="/facts/Van_Allen_radiation_belt/XKnhnWK0">Van Allen radiation belt</a>. </p><p>Cosmic rays were studied aboard the space station <a href="/facts/Mir/pILadPoB">Mir</a> in the late 20th century, such as with the SilEye experiment.<a class="footnote-ref" id="fnref:10" href="#fn:10"><sup>10</sup></a> This studied the relationship between flashes seen by astronauts in space and cosmic rays, the <a href="/facts/Cosmic_ray_visual_phenomena/BqBVK0TL">cosmic ray visual phenomena</a>.<a class="footnote-ref" id="fnref:11" href="#fn:11"><sup>11</sup></a> </p><p>In December 1993, the <a href="/facts/Akeno_Giant_Air_Shower_Array/T6WuHXkc">Akeno Giant Air Shower Array</a> in Japan (abbreviated <a href="/facts/AGASA/T6WuHXkc">AGASA</a>) recorded one of the highest energy cosmic ray events ever observed.<a class="footnote-ref" id="fnref:12" href="#fn:12"><sup>12</sup></a> </p><p>In October 2003, the <a href="/facts/Pierre_Auger_Observatory/bSp1g2n6">Pierre Auger Observatory</a> in Argentina completed construction on its 100th surface detector and became the largest cosmic-ray array in the world.<a class="footnote-ref" id="fnref:13" href="#fn:13"><sup>13</sup></a> It detects cosmic rays through the use of two different methods: watching <a href="/facts/Cherenkov_radiation/lSPJAC3U">Cherenkov radiation</a> made when particles interact with water, and observing ultraviolet light emitted in the Earth's atmosphere.<a class="footnote-ref" id="fnref:14" href="#fn:14"><sup>14</sup></a> In 2018, the installation of an upgrade called AugerPrime has started adding scintillation and radio detectors to the Observatory. </p><p>In 2010, an expanded version of <a href="/facts/Antarctic_Muon_And_Neutrino_Detector_Array/Lrv5B8QK">AMANDA</a> named <a href="/facts/IceCube_Neutrino_Observatory/N8Q2cCYF">IceCube</a> was completed. IceCube measures <a href="/facts/Cherenkov_radiation/lSPJAC3U">Cherenkov light</a> in a cubic kilometer of transparent ice. It is estimated to detect 275 million cosmic rays every day.<a class="footnote-ref" id="fnref:15" href="#fn:15"><sup>15</sup></a> </p><p>Space shuttle Endeavor transported the <a href="/facts/Alpha_Magnetic_Spectrometer/lcd9kQwf">Alphamagnetic Spectrometer (AMS)</a> to the <a href="/facts/International_Space_Station/VNPUBz9m">International Space Station</a> on May 16, 2011. In just over one year of operating, the AMS collected data on 17 billion cosmic-ray events.<a class="footnote-ref" id="fnref:16" href="#fn:16"><sup>16</sup></a> </p> <h2 id="observatories-and-experiments">Observatories and experiments</h2> <p>There are a number of cosmic ray research initiatives. These include, but are not limited to: </p> <ul><li>Ground based <ul><li>ALBORZ Observatory</li> <li>ERGO</li> <li><a href="/facts/CHICOS/jPVVREtI">CHICOS</a></li> <li><a href="/facts/GAMMA/w49woHwx">GAMMA</a></li> <li><a href="/facts/KASCADE/pJlNacpz">KASCADE</a>-(Grande) – KArlsruhe Shower Core and Array DEtector (and its extension called 'Grande')</li> <li><a href="/facts/Large_High_Altitude_Air_Shower_Observatory/7ynqtBmj">Large High Altitude Air Shower Observatory</a></li> <li><a href="/facts/LOPES_(telescope)/H9Ef48hg">LOPES</a> – the LOFAR PrototypE Station is the radio extension of KASCADE.</li> <li><a href="/facts/Tunka_experiment/NVWIUlaG">TAIGA</a> – Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy</li> <li><a href="/facts/High_Altitude_Water_Cherenkov_Experiment/wGzPmqQK">HAWC</a> High Altitude Water Cherenkov</li> <li><a href="/facts/High_Energy_Stereoscopic_System/Tw9ovaIw">High Energy Stereoscopic System</a></li> <li><a href="/facts/High_Resolution_Fly%2527s_Eye_Cosmic_Ray_Detector/NaPxj8Vp">High Resolution Fly's Eye Cosmic Ray Detector</a></li> <li><a href="/facts/MAGIC_(telescope)/bD8cTttJ">MAGIC (telescope)</a></li> <li><a href="/facts/MARIACHI/oBUu8IgU">MARIACHI</a></li> <li><a href="/facts/Pierre_Auger_Observatory/bSp1g2n6">Pierre Auger Observatory</a></li> <li>Project GRAND</li> <li><a href="/facts/SWGO/uF5AxMT6">Southern Wide-field Gamma-ray Observatory</a></li> <li><a href="/facts/Telescope_Array_Project/CUwpwY7S">Telescope Array Project</a></li> <li><a href="/facts/Washington_Large_Area_Time_Coincidence_Array/efISNSHw">WALTA (Washington Large Area Time Coincidence Array)</a></li> <li><a href="https://icecube.wisc.edu/science/icetop/">IceTop</a></li> <li><a href="https://web.archive.org/web/20140103141135/http://pcsati.com/apsd/">TACTIC</a></li> <li><a href="/facts/VERITAS/xylTuCUT">VERITAS</a></li> <li><a href="/facts/Major_Atmospheric_Cerenkov_Experiment_Telescope/xQuoPv6t">Major Atmospheric Cerenkov Experiment Telescope</a> (MACE)</li></ul></li> <li>Satellite based <ul><li><a href="/facts/Payload_for_Antimatter_Matter_Exploration_and_Light-nuclei_Astrophysics/4NP0zrff">PAMELA</a></li> <li><a href="/facts/Alpha_Magnetic_Spectrometer/lcd9kQwf">Alpha Magnetic Spectrometer</a></li> <li><a href="/facts/Spaceship_Earth_(detector)/Qwps87Qj">Spaceship Earth</a></li> <li><a href="/facts/Advanced_Composition_Explorer/LyrvNMgF">ACE (Advanced Composition Explorer)</a></li> <li><a href="/facts/Voyager_1/39jCxR9I">Voyager 1</a> and <a href="/facts/Voyager_2/9FAEaHUr">Voyager 2</a></li> <li><a href="/facts/Cassini-Huygens/PWknrDeY">Cassini-Huygens</a></li> <li><a href="/facts/1st_High_Energy_Astronomy_Observatory/fdqmWHpK">HEAO 1</a>, <a href="/facts/Einstein_Observatory/uNqeLETj">Einstein Observatory (HEAO2)</a>, <a href="/facts/3rd_High_Energy_Astronomy_Observatory/fIuyJ2tR">HEAO 3</a></li> <li><a href="/facts/ISS-CREAM/SFXkHxkY">ISS-CREAM</a></li></ul></li> <li>Balloon-borne <ul><li><a href="/facts/BESS_(experiment)/I4HLNQ17">BESS (Balloon-borne Experiment with Superconducting Spectrometer)</a></li> <li><a href="/facts/Advanced_Thin_Ionization_Calorimeter/h4FJ4HCs">ATIC (Advanced Thin Ionization Calorimeter)</a></li> <li><a href="/facts/TRACER_(cosmic_ray_detector)/yDwRmJyt">TRACER (cosmic ray detector)</a></li> <li><a href="/facts/BOOMERanG_experiment/ADxS37zv">BOOMERanG experiment</a></li> <li>TIGER <a href="https://tiger.gsfc.nasa.gov/">[1]</a> <a href="https://web.archive.org/web/20120503185934/http://tiger.gsfc.nasa.gov/">Archived</a> 2012-05-03 at the <a href="/facts/Wayback_Machine/nmQ3a6JC">Wayback Machine</a></li> <li><a href="/facts/Cosmic_Ray_Energetics_and_Mass/SFXkHxkY">Cosmic Ray Energetics and Mass</a> (CREAM)</li> <li><a href="http://www.bartol.udel.edu/gp/balloon/">AESOP</a> (Anti-Electron Sub-Orbital Payload)</li> <li><a href="/facts/General_antiparticle_spectrometer/BLU3ICAs">General antiparticle spectrometer</a> (GAPS)</li></ul></li></ul> <h2 id="ultra-high-energy-cosmic-rays">Ultra high energy cosmic rays</h2> <p>Observatories for <a href="/facts/Ultra-high-energy_cosmic_ray/DqeCybD9">ultra-high-energy cosmic rays</a>: </p> <ul><li><a href="/facts/MARIACHI/oBUu8IgU">MARIACHI</a> – Mixed Apparatus for Radar Investigation of Cosmic-rays of High Ionization located on Long Island, USA.</li> <li><a href="/facts/GRAPES-3/4tPq0YdN">GRAPES-3</a> (Gamma Ray Astronomy PeV EnergieS 3rd establishment) is a project for cosmic ray study with air shower detector array and large area muon detectors at Ooty in southern India.</li> <li><a href="/facts/AGASA/T6WuHXkc">AGASA</a> – Akeno Giant Air Shower Array in Japan</li> <li><a href="/facts/High_Resolution_Fly%2527s_Eye_Cosmic_Ray_Detector/NaPxj8Vp">High Resolution Fly's Eye Cosmic Ray Detector</a> (HiRes)</li> <li><a href="http://eas.ysn.ru/">Yakutsk Extensive Air Shower Array</a><a class="footnote-ref" id="fnref:17" href="#fn:17"><sup>17</sup></a></li> <li><a href="/facts/Pierre_Auger_Observatory/bSp1g2n6">Pierre Auger Observatory</a></li> <li><a href="/facts/Extreme_Universe_Space_Observatory/K0y5geol">Extreme Universe Space Observatory</a></li> <li><a href="/facts/Telescope_Array_Project/CUwpwY7S">Telescope Array Project</a></li> <li><a href="/facts/Antarctic_Impulse_Transient_Antenna/vDrDlUfB">Antarctic Impulse Transient Antenna</a> (ANITA) detects ultra-high-energy cosmic <a href="/facts/Neutrino/yGWVfSg2">neutrinos</a> believed to be caused by ultra-high-energy cosmic rays</li> <li>The COSMICi project at <a href="/facts/Florida_A%2526M_University/L0e54xBk">Florida A&M University</a> is developing technology for a distributed network of low-cost detectors for UHECR showers in collaboration with <a href="/facts/MARIACHI/oBUu8IgU">MARIACHI</a>.</li></ul> <h2 id="see-also">See also</h2> <ul><li><a href="/facts/Cosmic-Ray_Extremely_Distributed_Observatory/n98q9SJ5">CREDO</a></li> <li><a href="/facts/Extragalactic_cosmic_ray/IPwA5s0q">Extragalactic cosmic ray</a></li> <li>Gamma-ray telescopes (Alphabetic list)</li> <li><a href="/facts/Gamma-ray_astronomy/s59YdwaX">Gamma-ray astronomy</a> and <a href="/facts/X-ray_astronomy/KAQ6WxgQ">X-ray astronomy</a></li> <li><a href="/facts/Cosmic_Ray_System/0mQvADYR">Cosmic Ray System</a> (CR instrument on the Voyagers)</li></ul> <h2 id="further-reading">Further reading</h2> <ul><li>The Pierre Auger Collaboration (2007). "Correlation of the Highest-Energy Cosmic Rays with Nearby Extragalactic Objects". <i><a href="/facts/Science_(journal)/uTyzjkwD">Science</a></i>. 318 (5852): 938–943. <a href="/facts/ArXiv_(identifier)/H6EtgnBe">arXiv</a>:<a href="https://arxiv.org/abs/0711.2256">0711.2256</a>. <a href="/facts/Bibcode_(identifier)/9HtdQSGB">Bibcode</a>:<a href="https://ui.adsabs.harvard.edu/abs/2007Sci...318..938P">2007Sci...318..938P</a>. <a href="/facts/Doi_(identifier)/muM9Etpq">doi</a>:<a href="https://doi.org/10.1126%2Fscience.1151124">10.1126/science.1151124</a>. <a href="/facts/PMID_(identifier)/JlHAvMHt">PMID</a> <a href="https://pubmed.ncbi.nlm.nih.gov/17991855">17991855</a>. <a href="/facts/S2CID_(identifier)/ldJsHa2Y">S2CID</a> <a href="https://api.semanticscholar.org/CorpusID:118376969">118376969</a>.</li> <li>Clay, Roger; Dawson, Bruce (1997). <i>Cosmic Bullets: High Energy Particles in Astrophysics</i>. Cambridge, MA: <a href="/facts/Perseus_Books/VrSft6fY">Perseus Books</a>. <a href="/facts/ISBN_(identifier)/15AdSPa9">ISBN</a> 978-0-7382-0139-9. → A good introduction to ultra-high energy cosmic rays.</li> <li>Elbert, Jerome W.; Sommers, Paul (1995). "In search of a source for the 320 EeV Fly's Eye cosmic ray". <i>The Astrophysical Journal</i>. 441: 151–161. <a href="/facts/ArXiv_(identifier)/H6EtgnBe">arXiv</a>:<a href="https://arxiv.org/abs/astro-ph/9410069">astro-ph/9410069</a>. <a href="/facts/Bibcode_(identifier)/9HtdQSGB">Bibcode</a>:<a href="https://ui.adsabs.harvard.edu/abs/1995ApJ...441..151E">1995ApJ...441..151E</a>. <a href="/facts/Doi_(identifier)/muM9Etpq">doi</a>:<a href="https://doi.org/10.1086%2F175345">10.1086/175345</a>. <a href="/facts/S2CID_(identifier)/ldJsHa2Y">S2CID</a> <a href="https://api.semanticscholar.org/CorpusID:15510276">15510276</a>.</li> <li>Seife, Charles (2000). "Fly's Eye Spies Highs in Cosmic Rays' Demise". <i>Science</i>. 288 (5469): 1147. <a href="/facts/Doi_(identifier)/muM9Etpq">doi</a>:<a href="https://doi.org/10.1126%2Fscience.288.5469.1147a">10.1126/science.288.5469.1147a</a>. <a href="/facts/S2CID_(identifier)/ldJsHa2Y">S2CID</a> <a href="https://api.semanticscholar.org/CorpusID:117341691">117341691</a>.</li></ul> <h2 id="external-links">External links</h2> <ul><li><a href="https://books.google.com/books?id=QSgDAAAAMBAJ&pg=PA60">"Strange Instrument Built To Solve Mystery Of Cosmic Rays", April 1932, Popular Science</a></li> <li><a href="http://www.cosmic-ray.org/reading/flyseye.html#SEC10">The Highest Energy Particle Ever Recorded</a> The details of the event from the official site of the Fly's Eye detector.</li> <li><a href="/facts/John_Walker_(programmer)/rShfEVsN">John Walker</a>'s lively <a href="http://www.fourmilab.ch/documents/OhMyGodParticle/">analysis of the 1991 event</a>, published in 1994</li> <li><i><a href="http://www.bioedonline.org/news/news-print.cfm?art=1509">Origin of energetic space particles pinpointed</a></i>, by Mark Peplow for news@nature.com, published January 13, 2005.</li> <li><a href="https://web.archive.org/web/20121230225902/http://www.ift.uam.es/paginaspersonales/bellido/gravitacion/exp/CR_en.html">List of cosmic ray detectors</a> (archived 30 December 2012)</li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>Wolter, H. (1952). "Glancing Incidence Mirror Systems as Imaging Optics for X-rays". Annalen der Physik. 10 (1–2): 94–114. Bibcode:1952AnP...445...94W. doi:10.1002/andp.19524450108. <a href="/wiki/Bibcode_(identifier)" target="_blank">/wiki/Bibcode_(identifier)</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>Wolter, H. (1952). "Verallgemeinerte Schwarzschildsche Spiegelsysteme streifender Reflexion als Optiken für Röntgenstrahlen". Annalen der Physik. 10 (4–5): 286–295. Bibcode:1952AnP...445..286W. doi:10.1002/andp.19524450410. <a href="/wiki/Bibcode_(identifier)" target="_blank">/wiki/Bibcode_(identifier)</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>GSFC Gamma-Ray Telescopes & Detectors <a href="https://web.archive.org/web/19980224190201/http://imagine.gsfc.nasa.gov/docs/science/how_l2/gamma_detectors.html" target="_blank">https://web.archive.org/web/19980224190201/http://imagine.gsfc.nasa.gov/docs/science/how_l2/gamma_detectors.html</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>GSFC Gamma-Ray Telescopes & Detectors <a href="https://web.archive.org/web/19980224190201/http://imagine.gsfc.nasa.gov/docs/science/how_l2/gamma_detectors.html" target="_blank">https://web.archive.org/web/19980224190201/http://imagine.gsfc.nasa.gov/docs/science/how_l2/gamma_detectors.html</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>GSFC Gamma-Ray Telescopes & Detectors <a href="https://web.archive.org/web/19980224190201/http://imagine.gsfc.nasa.gov/docs/science/how_l2/gamma_detectors.html" target="_blank">https://web.archive.org/web/19980224190201/http://imagine.gsfc.nasa.gov/docs/science/how_l2/gamma_detectors.html</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p>"The discovery of air-Cherenkov radiation". 18 July 2012. <a href="http://cerncourier.com/cws/article/cern/50222" target="_blank">http://cerncourier.com/cws/article/cern/50222</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li> <li id="fn:7"><p>Galbraith, W.; Jelley, J.V. (1952). "Light Pulses from the Night Sky associated with Cosmic Rays". Nature. 171 (4347): 349–350. Bibcode:1953Natur.171..349G. doi:10.1038/171349a0. S2CID 4249692. <a href="/wiki/Bibcode_(identifier)" target="_blank">/wiki/Bibcode_(identifier)</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li> <li id="fn:8"><p>"Explorer-I and Jupiter-C". Data Sheet. Department of Astronautics, National Air and Space Museum, Smithsonian Institution. Retrieved 2008-02-09. <a href="https://history.nasa.gov/sputnik/expinfo.html" target="_blank">https://history.nasa.gov/sputnik/expinfo.html</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li> <li id="fn:9"><p>"Cosmic-Ray Detector". NSSDC Master Catalog. NASA. Retrieved 2008-02-09. <a href="https://nssdc.gsfc.nasa.gov/nmc/experiment/display.action?id=1958-001A-01" target="_blank">https://nssdc.gsfc.nasa.gov/nmc/experiment/display.action?id=1958-001A-01</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></p></li> <li id="fn:10"><p>Bidoli, V; Casolino, M; De Pascale, MP; Furano, G; Morselli, A; Narici, L; Picozza, P; Reali, E; Sparvoli, R; Galper, AM; Ozerov YuV, Popov AV; Vavilov, NR; Alexandrov, AP; Avdeev, SV; Yu, Baturin; Yu, Budarin; Padalko, G; Shabelnikov, VG; Barbellini, G; Bonvicini, W; Vacchi, A; Zampa, N; Bartalucci, S; Mazzenga, G; Ricci, M; Adriani, O; Spillantini, P; Boezio, M; Carlson, P; Fuglesang, C; Castellini, G; Sannita, WG (2000). "Study of cosmic rays and light flashes on board Space Station MIR: the SilEye experiment". Adv Space Res. 25 (10): 2075–9. Bibcode:2000AdSpR..25.2075B. doi:10.1016/s0273-1177(99)01017-0. PMID 11542859. <a href="/wiki/Bibcode_(identifier)" target="_blank">/wiki/Bibcode_(identifier)</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></p></li> <li id="fn:11"><p>Bidoli, V; Casolino, M; De Pascale, MP; Furano, G; Morselli, A; Narici, L; Picozza, P; Reali, E; Sparvoli, R; Galper, AM; Ozerov YuV, Popov AV; Vavilov, NR; Alexandrov, AP; Avdeev, SV; Yu, Baturin; Yu, Budarin; Padalko, G; Shabelnikov, VG; Barbellini, G; Bonvicini, W; Vacchi, A; Zampa, N; Bartalucci, S; Mazzenga, G; Ricci, M; Adriani, O; Spillantini, P; Boezio, M; Carlson, P; Fuglesang, C; Castellini, G; Sannita, WG (2000). "Study of cosmic rays and light flashes on board Space Station MIR: the SilEye experiment". Adv Space Res. 25 (10): 2075–9. Bibcode:2000AdSpR..25.2075B. doi:10.1016/s0273-1177(99)01017-0. PMID 11542859. <a href="/wiki/Bibcode_(identifier)" target="_blank">/wiki/Bibcode_(identifier)</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></p></li> <li id="fn:12"><p>"Cosmic rays | CERN timelines". timeline.web.cern.ch. Archived from the original on 2017-09-15. Retrieved 2017-09-15. <a href="https://web.archive.org/web/20170915204601/http://timeline.web.cern.ch/timelines/Cosmic-rays?page=2" target="_blank">https://web.archive.org/web/20170915204601/http://timeline.web.cern.ch/timelines/Cosmic-rays?page=2</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></p></li> <li id="fn:13"><p>"Cosmic rays | CERN timelines". timeline.web.cern.ch. Archived from the original on 2017-09-15. Retrieved 2017-09-15. <a href="https://web.archive.org/web/20170915204601/http://timeline.web.cern.ch/timelines/Cosmic-rays?page=2" target="_blank">https://web.archive.org/web/20170915204601/http://timeline.web.cern.ch/timelines/Cosmic-rays?page=2</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></p></li> <li id="fn:14"><p>"Cosmic rays | CERN timelines". timeline.web.cern.ch. Archived from the original on 2017-09-15. Retrieved 2017-09-15. <a href="https://web.archive.org/web/20170915204601/http://timeline.web.cern.ch/timelines/Cosmic-rays?page=2" target="_blank">https://web.archive.org/web/20170915204601/http://timeline.web.cern.ch/timelines/Cosmic-rays?page=2</a> <a href="#fnref:14" class="footnote-back-ref">↩</a></p></li> <li id="fn:15"><p>"Cosmic rays | CERN timelines". timeline.web.cern.ch. Archived from the original on 2017-09-15. Retrieved 2017-09-15. <a href="https://web.archive.org/web/20170915204601/http://timeline.web.cern.ch/timelines/Cosmic-rays?page=2" target="_blank">https://web.archive.org/web/20170915204601/http://timeline.web.cern.ch/timelines/Cosmic-rays?page=2</a> <a href="#fnref:15" class="footnote-back-ref">↩</a></p></li> <li id="fn:16"><p>"Cosmic rays | CERN timelines". timeline.web.cern.ch. Archived from the original on 2017-09-15. Retrieved 2017-09-15. <a href="https://web.archive.org/web/20170915204601/http://timeline.web.cern.ch/timelines/Cosmic-rays?page=2" target="_blank">https://web.archive.org/web/20170915204601/http://timeline.web.cern.ch/timelines/Cosmic-rays?page=2</a> <a href="#fnref:16" class="footnote-back-ref">↩</a></p></li> <li id="fn:17"><p>"EAS". Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy of Siberian Branch of the Russian Academy of Sciences. Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy of SB RAS. Retrieved 30 May 2021. <a href="https://ikfia.ysn.ru/en/eas/" target="_blank">https://ikfia.ysn.ru/en/eas/</a> <a href="#fnref:17" class="footnote-back-ref">↩</a></p></li> </ol>