Random Creepy Facts About Outer Space You Can't Unlearn (25 items)

(#23) Tears Don't Fall In Space

While astronauts can physically cry in space, zero gravity prevents tears from flowing down the face––instead, they ball up and "conglomerate around the eyeball."
(#15) Feces Float

The crew members of Apollo 10 discovered that the makeup of feces combined with the diet of astronauts rendered it bouncy and pong-like. At one point during the mission, feces was loosed from its container due to its sponginess, causing a stir among the astronauts.
(#13) There Are Sounds In Space

Though popular thought contends that outer space is a vacuum, in actuality -- interstellar dust is so dense in some areas that it can carry sound waves. Though these waves would be imperceptive to humans.

Some sounds in space may include the humming of a massive black hole, the groans of Earth as its crust shifts, and the residual sound of the universe expanding.
(#18) Water Can Start Fires In Space

In 2014, scientists experimented "supercritical" water, a state of water that occurs when it is compressed to a pressure of 217 atmospheres and heated above 373 degrees Celsius. When mixed with organic material, it creates a liquid-like gas that creates a burning effect, though with no flame.

Astronauts often use supercritical water as a means to dispose of waste.
(#3) The Night Sky Will Someday Be Completely Black

As the Milky Way Galaxy continues to merge with its neighboring galaxies, the view of the night sky from Earth will change dramatically. The speedy expansion will eventually pull the galaxies apart faster than light, eliminating the distinctive products of the big bang and nullifying points of reference for expansion measurement.
(#9) After A Month In Orbit, Callouses Slough Off

Scott Kelly, the same astronaut who returned from the International Space Station with numerous genetic changes, revealed in a Reddit AMA that, in space, foot callouses will eventually slough off:

The bottoms of your feet become very soft like newborn baby feet. But the top of my feet develop rough alligator skin because I use the top of my feet to get around here on space station when using foot rails.