Nickelodeon unveiled a video of ISS astronauts enjoying its green slime on May 2, 2020 (Credit: Nickelodeon)

Nickelodeon's annual Kids Choice Awards show is notorious for dumping buckets of green slime on the heads of unsuspecting hosts and celebrities. Fortunately for the winners, that was not possible during this year's virtual award ceremony, aired on May 2, 2020. To compensate, the popular children's cable channel surprised the millions of online viewers with footage of International Space Station (ISS) astronauts getting "slimed". The video's debut was particularly timely given that May 2, 2020, was National Astronomy Day!

"Slime in Space" began with NASA astronaut Christina Koch carefully cutting open the "Slime Bag," sent to the ISS aboard a SpaceX Dragon spacecraft in July 2019, and squeezing out a portion of the gooey mixture through a straw. Instead of plopping straight to the ground as it would have on Earth, the viscous liquid formed a perfectly-circular globe and began floating around, causing the delighted astronaut to proclaim, "Boom! Houston, we have a slime blob."

Koch and fellow astronaut Luca Parmitano from the European Space Agency (ESA) then attempted several other fun experiments, including rotating the slime ball around and even using the green mix to play ping-pong. "Playing with slime in space is way more fun than I thought it would be — and way more unpredictable," Koch later said. "Just like all of the other science we do, you cannot replicate these experiments on the Earth, you need zero gravity to see some of this behavior."

However, no slime experience is complete without getting splattered with the substance. "Ahh! I'm slimed!" yelled Koch while laughing, as Parmitano sprayed the green goo on her arm and across her shirt.

ESA's Luca Parmitano (L) and NASA's Christina Koch (R) conducted several fun experiments to test slime in microgravity (Credit: Nickelodeon)

While the astronauts, who have both returned to Earth since the video was filmed in September 2019, certainly had fun, "Slime in Space" had a more serious purpose. It was part of NASA's "Non-Newtonian Fluids in Microgravity" project — its mission is to create educational videos and other content to promote science, technology, engineering, and mathematics (STEM) to elementary and middle school students worldwide.

"Slime is a non-Newtonian fluid, a material in which its viscosity (resistance to flow) changes based on the amount of shear stress applied to it — for example, through squeezing or stirring," explained the Center for the Advancement of Science in Space (CASIS), the non-profit organization that manages the ISS National Lab for NASA.

Parmitano used the slime to play ping-pong in Space (Credit: Nickelodeon)

To enable kids to understand why the green liquid behaves differently in microgravity, Nickelodeon also developed an in-depth educational video. Entitled "Nickelodeon Slime in Space: A Virtual Field Trip," the 15-minute-long footage shows children on Earth mimicking the ISS astronaut demonstrations. Though the outcomes were very different, they were equally entertaining!

Resources: NASA.gov, www.issnationallab.org