Marshmallows in Space

Science At Home People and Place

What would happen to a marshmallow in space?

Join OMSI Educator Glenford as he tests everything from marshmallows to slime inside a vacuum bell jar, a system that simulates the zero atmosphere environment of space. Will anything survive? 

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The air on Earth is made up of gas molecules – we call this atmosphere. All those molecules floating around us apply 14.7 pounds of atmospheric pressure per square inch. That’s a lot of pressure pushing on our bodies and our marshmallows at all times! 

Unlike Earth, space is a vacuum. Not the kind of vacuum cleaner you use on a rug, but the scientific kind of vacuum where there are no air molecules and therefore zero atmospheric pressure. 

If you traveled to space and forgot to wear a pressurized space suit, you would die within a couple of minutes. Without atmospheric pressure, the boiling point of water decreases. Human bodies are about 60% water, and all that water would begin to boil, changing from a liquid into a gas. This would cause our tissues to puff up and our bodies to cool down. To make matters worse, the vacuum of space would pull all the air out of our lungs! Not a fun way to go… 

Some things do okay in space! These objects tend to be solid and not alive, making them less affected by the cold, zero pressure environment.


Atmosphere: the layer of gas molecules that surrounds Earth or other planets. 

Boiling point: the temperature at which a liquid boils and turns into a gas

Top Image Credit: NASA

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