MicroFactzzz#0022 · 🌌 Cosmic Oddities
Astronauts See Mysterious Flashes of Light Even With Their Eyes Closed
Beyond Earth's atmosphere, high-energy cosmic particles pass straight through the retina, triggering visible flashes even in total darkness.
Since the Apollo missions, astronauts have reported a strange phenomenon: they see brief flashes, streaks, or spots of light even with their eyes closed, in complete darkness.
The cause is cosmic rays — high-energy particles (mostly protons and heavier atomic nuclei) traveling at nearly the speed of light, which on Earth are mostly blocked by the thick atmosphere and the planet's magnetic field.
Without that protection, these particles can pass directly through the eyeball, interacting with the retina or optic nerve in a way the brain interprets as a flash of light — even though no actual light ever reached the eye.
This phenomenon is one reason long space missions, like a potential trip to Mars, raise concerns about cumulative exposure to cosmic radiation.
Sources
- General knowledge / encyclopedic sources
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Krulicza Nora
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