Scott Solomon

But but we are.

And so our muscles, for example, in our in our legs and in our back, they are helping to hold us up.

And when you don't have to do that anymore, those muscles start to weaken.

And and so astronauts have to do two hours of exercise every single day that they're in space just to kind of minimize the amount of muscle atrophy

That happens, but it still happens.

And then interestingly, the bones in our body respond to muscle.

So when the muscles aren't working as hard, the bones respond by actually giving up some of the materials, the minerals like calcium and phosphorus that give our bones strength.

those minerals start to be basically removed from the bone.

And so it causes the bones to weaken and become more brittle.

So astronauts lose bone density at a rate of about 1.5% to 2% per month that they're in space.

And so if you're in space for multiple years, as would be necessary, for example, if you go to Mars, that could really be a long readjustment to coming back to Earth.

And it might be quite dangerous.

Well, that's a great question.

So I mean, yeah, a lot of science fiction depictions of being in space do kind of take liberties when it comes to things like gravity.

So the idea that you're going to be flying around between planets and walking around your spacecraft as if you were walking on Earth, that's pretty unrealistic.

We have not yet developed technologies that allow us to have artificial gravity.

I mean, there's concepts out there.

You could have a giant rotating

like a centrifuge basically on a spacecraft.

That's an idea that has been explored in science fiction, but we're nowhere near actually having that kind of technology in real life.