6. In zero gravity, a candle’s flame is round and blue. – Source.
7. The zero-gravity scenes in the Apollo 13 movie are actually real. The crew filmed 4 hours of material in 612 parabola flights. – Source.
8. The tallest possible mountains on a neutron star can only be about 5mm tall due to their gravity. – Source.
9. NASA cannot bring birds into space because birds need gravity to swallow.
10. Humans usually get the urge to pee when the bladder is just 1/3 full. But in zero gravity, the urge doesn’t kick in till the bladder is almost completely full. When astronaut John Glenn orbited the Earth, his only urination was 27 ounces, seven ounces more than the capacity of the average human bladder. – Source