• tal@lemmy.todayEnglish
      141·
      2 days ago

      https://en.wikipedia.org/wiki/Cosmic_ray_visual_phenomena

      Cosmic ray visual phenomena, or light flashes (LF), also known as Astronaut’s Eye, are spontaneous flashes of light visually perceived by some astronauts outside the magnetosphere of the Earth, such as during the Apollo program. While LF may be the result of actual photons of visible light being sensed by the retina,[1] the LF discussed here could also pertain to phosphenes, which are sensations of light produced by the activation of neurons along the visual pathway.[2]

      Researchers believe that the LF perceived specifically by astronauts in space are due to cosmic rays (high-energy charged particles from beyond the Earth’s atmosphere[3]), though the exact mechanism is unknown. Hypotheses include Cherenkov radiation created as the cosmic ray particles pass through the vitreous humour of the astronauts’ eyes,[4][5] direct interaction with the optic nerve,[4] direct interaction with visual centres in the brain,[6] retinal receptor stimulation,[7] and a more general interaction of the retina with radiation.[8]

      The main shapes seen are “spots” (or “dots”), “stars” (or “supernovas”), “streaks” (or “stripes”), “blobs” (or “clouds”) and “comets”. These shapes were seen at varying frequencies across astronauts. On the Moon flights, astronauts reported seeing the “spots” and “stars” 66% of the time, “streaks” 25% of the time, and “clouds” 8% of the time.[10] Astronauts who went on other missions reported mainly “elongated shapes”.[9] About 40% of those surveyed reported a “stripe” or “stripes” and about 20% reported a “comet” or “comets”. 17% of the reports mentioned a “single dot” and only a handful mentioned “several dots”, “blobs” and a “supernova”.

      A reporting of motion of the LF was common among astronauts who experienced the flashes.[9] For example, Jerry Linenger reported that during a solar storm, they were directional and that they interfered with sleep since closing his eyes would not help. Linenger tried shielding himself behind the station’s lead-filled batteries, but this was only partly effective.[11]

      There are a lot of not-immediately-obvious benefits to being on Earth.