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Email Exclusive: Galaxy Slime

It’s slime time! Kids love getting their hands on this ooey, gooey, sticky goop. Enjoy our space-themed recipe for glow-in-the-dark slime, and expand your explorers’ horizons with the cool science behind it.


  • 1 cup glow-in-the-dark glue
  • 2 cups warm water
  • 1 teaspoon borax (sodium tetraborate) as slime activator
  • Glitter (optional)
  • Space charms (optional)


  1. Pour glow-in-the-dark glue into a mixing bowl.
  2. Mix warm water and borax in a separate container.
  3. Add warm water and borax to the glow-in-the-dark glue.
  4. Stir until the slime reaches the desired consistency.
  5. Add glitter and space charms, then mix until they’re well distributed.
  6. Turn out the lights and play!

Discover the Science

At Little Passports, we believe in discovering the world through play. Curious about the science of slime? Here are some fascinating facts to feed your explorer while they get messy.

  • This slime is stretchy because of flexible chain-like molecules in the glue called polymers. When a slime activator is mixed with the glue, the molecules cross-link, so they don’t flow past each other as easily. When the slime is puddled up, its polymer chains mush together. When you stretch out the slime, the polymer chains straighten, but they don’t break. That’s why slime stretches so well!
  • In 2020, astronauts brought slime into space to conduct experiments. It was a little different from our galaxy slime, but it did some cool things. Without gravity, it formed into a sphere, and when the astronauts played with it, they found they could spin it, squirt it, make it bounce up and down on a paddle, and more!
  • If you’ve ever picked up a rock covered in slippery green goo from a river or lake, you might have thought it was covered in slime. But those rocks are actually covered in cyanobacteria, one of the oldest forms of life on Earth. Scientists once put trays of cyanobacteria into space outside the International Space Station, and the bacteria survived for over a year! Cyanobacteria could be used in space to make biological radiation shields or even change other planets to make them more habitable for humans!

More Activities

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Looking for more space fun? Launch a six-month journey beyond the Earth with Little Passports’ Space Quest subscription! Ignite galactic curiosity through 11 hands-on projects tied together by a story featuring six diverse kid astronauts, plus six beautifully illustrated posters. Make a room into a planetarium, launch a rocket, build a deep space maze, grow alien lifeforms, and more!

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