What happens to our bodies in space? Spark curiosity with 3 easy activities at home!
Astronauts Sunita Williams and Barry Wilmore embarked on their mission to the International Space Station (ISS) in June 2024. Originally planned as a brief eight-day stay, their mission was unexpectedly extended and now they may be in space longer than six months! So what happens to human bodies when they spend long periods of time in space? Keep reading for some fun ways you can experiment at home to understand the effects of space on our bodies!
In this photo provided by NASA, astronauts Butch Wilmore, left, and Suni Williams inspect safety hardware aboard the International Space Station on Aug. 9, 2024. (NASA)
🧠 The Effects of Space on Our Bodies
Ever noticed how when you toss a ball in the air, it always comes back down?
Or when you jump high, you always come back down–that’s gravity at work!
Here on Earth, gravity is an invisible force pulling us—and everything else—toward the ground. It's the reason we can walk, run, and jump without floating away. Gravity doesn’t just work on small things—it’s also what keeps the oceans from floating into space and makes the planets orbit the sun. But in space, gravity is almost nonexistent. Instead of walking, astronauts float, which sounds super fun but also leads to some changes in their bodies:
🦴 Bones and Muscles: Without the pull of gravity, an astronaut’s bones and muscles aren’t working as hard as they do on Earth. Over time, they can weaken.
🩸 Blood Flow: Gravity helps keep blood flowing through our bodies, but in space, blood moves differently, sometimes making astronauts feel puffy-faced.
👂 Balance: Our inner ears help us balance on Earth, but in space, this system can get confused, making it tricky to know which way is up or down.
🔍 Explore minimal gravity in space with 3 kid-friendly activities
Sometimes concepts like “gravity” can be hard for little ones to grasp without exploring themselves! Gather your little astronauts for three down-to-earth demonstrations to start conversations about gravity and the differences between Earth and space. Remember these simplified activities help prompt curiosity and discussion, but do not capture all the scientific nuances of these concepts. Check out the links at the end of this post to explore this topic further or to provide more resources to older children if they are interested!
Activity #1: The Floating Object Demonstration
What You’ll Need:
A ping pong ball or any lightweight object
A bowl of water
What to Do:
Place the ball in the bowl of water and watch it float. This mimics how astronauts float in space due to the lack of gravity. Gently push it down and observe how it pops back up, just like an astronaut might!
Activity #2: Modeling Why Bones and Muscles Can Weaken In Space
What You’ll Need:
One heavy book (with lots of pages)
One light book (with fewer pages)
What to Do: Hold your hands out, palms up. Place the heavy book in one hand and the lighter book in the other. The heavy book represents Earth’s gravity, where our muscles and bones have to work hard to support us. The lighter book represents space, where there’s much less resistance on the body. Over time, because the muscles and bones don’t have to work as much in space, they can weaken. That’s why astronauts exercise a lot in space to keep their bodies strong!
Activity #3: The Balance Beam Challenge
What You’ll Need:
A long piece of tape or a rope
Blindfolds (optional)
What to do:
Create a straight line on the floor with tape or rope to simulate a balance beam. Walk the line with eyes open to maintain balance. Then, wear a blindfold or close your eyes and try to walk in a straight line. Talk about how much harder it is to balance without being able to see, similar to how astronauts might feel when their inner ear system is confused in space and they can’t figure out which way is up.
Curious to learn more?
Visit https://www.nasa.gov/learning-resources/nasa-kids-club/ or for grown-ups, start here: https://www.nasa.gov/humans-in-space/the-human-body-in-space/. Keep asking questions and exploring—there’s so much to discover out there!