Closing your eyes in space can cause a terrifying sensation

We all know what it feels like to fall.

If you've got a daredevil's bent, it's a thrill - that leap off a cliff into the blue water below.

For many, there's fear, a nightmare of a never-ending fall that recurs night after night.

But if you reside on the International Space Station, like astronaut Scott Kelly has been doing for more than 300 days already as part of a year in space, that never-ending fall is a feeling you may have to grow comfortable with.

As Kelly explained in a Reddit AMA question-and-answer session on January 24, it feels rather strange - physically - to live on a satellite orbiting our planet.

Redditor emshedoesit asked Kelly "What does zero G feel like on your body when you are just hanging out?"

Kelly replied:

It feels like there is no pressure at all on your body. Sometimes it feels like you are just hanging but you are not hanging by anything, just hanging there.

But what he said next was particularly fascinating:

If I close my eyes, I can give myself the sensation that I am falling. Which I am, I am falling around the Earth.

The Space Station falls constantly around the Earth, at a speed of more than 17,500 miles per hour. Earth's gravity keeps it in orbit, but that orbit is just a constant speedy fall around the globe.

So while most of the time it may feel like just hanging, not being drawn to the ground as we earthbound are; that feeling is caused by the weightlessness of a constant fall that doesn't end as long as you are up in space, a fall that goes around and around the planet.

Sounds pretty fun.