But certainly we haven't seen that and you know, maybe some day we will.
It's hard for me to say whether I truly believe it or not. I think it's possible. I don't believe we've seen anything but it's possible there is life out there somewhere.
CNN: @FumaiMartin asks how much physics and chemistry taught in high school helps at the International Space Station?
KN: I think any type of scientific class or mathematical class or any class really that you take is helpful even if you don't use the specific fundamentals that you learn in that class.
There is something about learning how to learn that I think is very important is a very broad spectrum. And the same for college, a lot of the classes you take you are like, you think to yourself 'I'm never going to use this.' And you know what, sometimes you don't ... But a lot of it you do use.
Even though we are working directly with the investigators of the scientific experiments. It's important for us understand what's going on so we can help and maybe we can see things and we can help them with their discoveries.
CNN: Greg Wagner on Facebook asks what one place on Earth would you most like to visit with only the knowledge of having seen it from the ISS?
KN: Oh wow! You know there are so many beautiful places that I don't even know how I would answer that.
I've seen some mountain ranges that are just absolutely incredible ... But at the same time, I've come along some coastlines that look just breathtaking and so I guess I would have a lot of traveling to do if I were to go to every single place that I thought looked like a great place to be.
CNN: CNN Mexico commenter Luis Flores Gonzalez asks if you were offered the opportunity to take a one-way trip to the deepest part of the universe, would you accept it?
KN: A one-way trip, no. Especially with the current situation I'm in with a young son and a husband at home. I definitely would not want to do a really long, and definitely a one-way trip.
It might be a different story if I had family with me but I'd have to say no to that.
CNN: @Fadhelindonesia asks when you read my message what continent are you looking at?
KN: We just passed over the east coast of South America and we are heading up towards Africa. We should be there in just a couple of minutes. And then we'll head up over Europe and into Asia.
CNN: Leading Women co-anchor Kristie Lu Stout tweeted: We hear you're a bit of a DIY design geek. Do you get crafty in space?
KN: I have been trying to do a little bit. ... It's amazing. Time goes by so fast and in the weekdays and on the evenings, there's absolutely no time for that.
Sundays is really my day and I actually got a few things out the other day and drew up a design on a piece of paper and cut up some old T shirts and have started sewing things together.
Not quite sure exactly how it is going to turn out but ... when I find the time to sit there and do that only, hopefully I'll get something done.