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  2. Cosmic ray visual phenomena - Wikipedia

    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 ...

  3. Health threat from cosmic rays - Wikipedia

    en.wikipedia.org/wiki/Health_threat_from_cosmic_rays

    Health threats from cosmic rays are the dangers posed by cosmic rays to astronauts on interplanetary missions or any missions that venture through the Van-Allen Belts or outside the Earth's magnetosphere. [ 1][ 2] They are one of the greatest barriers standing in the way of plans for interplanetary travel by crewed spacecraft, [ 3][ 4][ 5] but ...

  4. Spaceflight osteopenia - Wikipedia

    en.wikipedia.org/wiki/Spaceflight_osteopenia

    Spaceflight osteopenia refers to the characteristic bone loss that occurs during spaceflight. Astronauts lose an average of more than 1% bone mass per month spent in space. [ 1] There is concern that during long-duration flights, excessive bone loss and the associated increase in serum calcium ion levels will interfere with execution of mission ...

  5. Effect of spaceflight on the human body - Wikipedia

    en.wikipedia.org/wiki/Effect_of_spaceflight_on...

    The effects of spaceflight on the human body are complex and largely harmful over both short and long term. [ 1] Significant adverse effects of long-term weightlessness include muscle atrophy and deterioration of the skeleton ( spaceflight osteopenia ). [ 2] Other significant effects include a slowing of cardiovascular system functions ...

  6. Biological effects of high-energy visible light - Wikipedia

    en.wikipedia.org/wiki/Biological_effects_of_high...

    Blue light, a type of high-energy light, is part of the visible light spectrum. High-energy visible light (HEV light) is short-wave light in the violet/blue band from 400 to 450 nm in the visible spectrum, which has a number of purported negative biological effects, namely on circadian rhythm and retinal health (blue-light hazard), which can lead to age-related macular degeneration.

  7. Mass-to-light ratio - Wikipedia

    en.wikipedia.org/wiki/Mass-to-light_ratio

    In astrophysics and physical cosmology the mass-to-light ratio, normally designated with the Greek letter upsilon, ϒ, [ 1] is the quotient between the total mass of a spatial volume (typically on the scales of a galaxy or a cluster) and its luminosity. These ratios are often reported [why?] using the value calculated for the Sun as a baseline ...

  8. Coronal mass ejection - Wikipedia

    en.wikipedia.org/wiki/Coronal_mass_ejection

    Coronal mass ejections are usually visible in white-light coronagraphs. A coronal mass ejection ( CME) is a significant ejection of magnetic field and accompanying plasma mass from the Sun's corona into the heliosphere. CMEs are often associated with solar flares and other forms of solar activity, but a broadly accepted theoretical ...

  9. Stellar mass loss - Wikipedia

    en.wikipedia.org/wiki/Stellar_mass_loss

    Stellar mass loss is a phenomenon observed in stars by which stars lose some mass over their lives. Mass loss can be caused by triggering events that cause the sudden ejection of a large portion of the star's mass. It can also occur when a star gradually loses material to a binary companion or due to strong stellar winds.