Cosmic ray visual phenomena

Cosmic ray visual phenomena

Cosmic ray visual phenomena, also referred to as phosphenes or "light flashes", are spontaneous flashes of light visually perceived by astronauts outside the magnetosphere of the Earth, such as during the Apollo program. Researchers believe that cosmic rays are responsible for these flashes of light, though the exact mechanism is unknown. Hypotheses include one or all of: Cherenkov radiation created as the cosmic ray particles pass through the vitreous humor of the astronauts' eyes, direct interaction with the retina/optic nerve, or direct interaction with visual centres in the brain.[1]

Astronauts almost always reported that the flashes were white, with one exception in which the astronaut observed "blue with a white cast, like a blue diamond". There were a few different types of flashes: "spots" and "stars" were observed 66% of the time, "streaks" were observed 25% of the time, and "clouds" were observed 8% of the time.

Once their eyes became adapted to the dark, Apollo astronauts reported seeing this phenomenon once every 2.9 minutes on average. They also reported that they observed the phenomenon more frequently during the transit to the Moon than during the return transit to Earth.

During the Apollo 16 and Apollo 17 transits, astronauts conducted the ALFMED Experiment where an astronaut wore a helmet designed to capture the tracks of cosmic ray particles to determine if they coincided with the visual observation. Examination of the results showed that two of fifteen tracks coincided with observation of the flashes. These results in combination with considerations for geometry and Monte Carlo estimations led researchers to conclude that the visual phenomenon were indeed caused by cosmic rays.

More recently, the SilEye/Alteino and ALTEA projects have investigated the phenomenon aboard the International Space Station, using helmets similar in nature to those in the ALFMED experiment.

See also

References

  1. ^ Narici, L (1 January 2004). "The ALTEA/ALTEINO projects: studying functional effects of microgravity and cosmic radiation". Advances in Space Research 33 (8): 1352–1357. Bibcode 2004AdSpR..33.1352N. doi:10.1016/j.asr.2003.09.052. http://people.roma2.infn.it/~morselli/A94Altea.pdf. Retrieved 10 April 2011. 



Wikimedia Foundation. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • Cosmic-ray observatory — A cosmic ray observatory is a scientific installation built to detect high energy particles coming from space called cosmic rays. This typically includes photons (high energy light), electrons, protons, and some heavier nuclei, as well as… …   Wikipedia

  • X-ray astronomy — X rays start at 0.008 nm and extend across the electromagnetic spectrum to 8 nm, over which the Earth s atmosphere is opaque. X ray astronomy is an observational branch of astronomy which deals with the study of X ray observation and detection… …   Wikipedia

  • Cherenkov radiation — glowing in the core of the Advanced Test Reactor …   Wikipedia

  • Microwave auditory effect — The microwave auditory effect, also known as the microwave hearing effect or the Frey effect, consists of audible clicks induced by pulsed/modulated microwave frequencies. The clicks are generated directly inside the human head without the need… …   Wikipedia

  • star — starless, adj. /stahr/, n., adj., v., starred, starring. n. 1. any of the heavenly bodies, except the moon, appearing as fixed luminous points in the sky at night. 2. Astron. any of the large, self luminous, heavenly bodies, as the sun, Polaris,… …   Universalium

  • radiation — radiational, adj. /ray dee ay sheuhn/, n. 1. Physics. a. the process in which energy is emitted as particles or waves. b. the complete process in which energy is emitted by one body, transmitted through an intervening medium or space, and… …   Universalium

  • astronomy — /euh stron euh mee/, n. the science that deals with the material universe beyond the earth s atmosphere. [1175 1225; ME astronomie ( < AF) < L astronomia < Gk. See ASTRO , NOMY] * * * I Science dealing with the origin, evolution, composition,… …   Universalium

  • spectroscopy — spectroscopist /spek tros keuh pist/, n. /spek tros keuh pee, spek treuh skoh pee/, n. the science that deals with the use of the spectroscope and with spectrum analysis. [1865 70; SPECTRO + SCOPY] * * * Branch of analysis devoted to identifying… …   Universalium

  • Outline of astronomy — Mauna Kea in Hawaii is one of the world s premier observatory sites. Pictured is the W. M. Keck Observatory, an optical interferometer. The following outline is provided as an overview of and topical guide to astronomy: Astronomy – studies the… …   Wikipedia

  • List of unsolved problems in physics — This is a list of some of the major unsolved problems in physics. Some of these problems are theoretical, meaning that existing theories seem incapable of explaining a certain observed phenomenon or experimental result. The others are… …   Wikipedia

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”