Space myths
Space is already strange enough without the misconceptions layered on top by decades of movies and chain emails. A fact-checked tour — paired with the physics-flavored space myths over on science myths (gravity, seasons, and why sinks don't drain differently by hemisphere).
The Moon
Myth
The claim: There's a permanently 'dark side of the Moon' that never gets sunlight.
Actually: Every part of the Moon gets sunlight over its roughly month-long day-night cycle. What people usually mean is the far side — the hemisphere that always faces away from Earth — which gets plenty of daylight, it's just never visible from here.
Myth
The claim: We only ever see one side of the Moon because it doesn't rotate.
Actually: The Moon does rotate — once about every 27.3 days, which happens to exactly match the time it takes to orbit Earth. That match (called tidal locking) is why the same face always points our way, not an absence of spin.
The Sun & other planets
Myth
The claim: The Sun is yellow.
Actually: The Sun emits light across the visible spectrum and appears essentially white from space. Its yellow-orange look from Earth's surface comes from our atmosphere scattering blue light out of the direct beam — the same effect (Rayleigh scattering) that makes the sky blue.
Myth
The claim: Every August, Mars looks as big as the full Moon in the night sky.
Actually: This is a long-running viral hoax that resurfaces every year (it started as a genuine but wildly exaggerated 2003 email about an unusually close approach). Mars never appears anywhere near the size of the Moon to the naked eye.
Basic astronomy
Myth
The claim: A 'shooting star' is an actual star falling from the sky.
Actually: It's a small piece of rock or dust burning up from friction in Earth's atmosphere — a meteor. Real stars are enormous, distant suns; nothing that small could be one.
Myth
The claim: Space is a perfect, total vacuum with absolutely nothing in it.
Actually: Space contains sparse matter — thin interstellar gas, dust and cosmic rays — even though it's a vastly better vacuum than anything achievable on Earth. 'Empty' is relative, not absolute.
Myth
The claim: If you're exposed to the vacuum of space unprotected, your blood boils instantly and your body explodes.
Actually: Movie physics, not real physics. Unprotected exposure is genuinely dangerous and can cause gases in body fluids to bubble (a real effect called ebullism), but there's no explosion, and brief, accidental exposures documented by NASA have been survived with quick recompression.
For the everyday physics of gravity, seasons and the Coriolis effect, see science myths. For how a hoax like the Mars myth spreads and refuses to die every single year, see media literacy.