Jet Propulsion and Microscopic!

Dear Blue Families,

We recently learned about Medusa Jellyfish (AKA Alarm Jellies, Atolla Jellies, or Coronate Medusa ) which move by jet propulsion. They¬†contract and relax a ring of muscles around the bell. The muscles open and close the bell, drawing in water and then forcing it out again to push the jellyfish forward. To gain a better understanding of this unique type of movement, we recreated it. First, with a parachute mimicking a Medusa Jelly’s undulating bell. Students were the ring of muscles around the bell that contracted and relaxed to fill the parachute.¬† Then, with demonstrations using a water balloon in a tank of water to see how jet propulsion pushes them through the water.

Click the links below to see this in action!

Undulating Parachute!
Jet Propulsion in a Tank!


Previously in Blue Class, we borrowed some microscopes to check out Tardigrades AKA Water Bears! Water Bears are microscopic animals that are found in the Midnight Zone with many unique and fascinating adaptations. Read below to see observations made by students about these tiny but fierce creatures.

“One was eating another!” Zeno

“They looked like clear glue with loose green stuff on them.” Jonathan

“They were swimming around!”¬† Liam

“I saw one cannibalizing another one!” Kelly

“They looked like they were fighting, they were hoping on each other.” Buck

“They moved around alot.” Sidney

“They had little eight legs that move at the same time.” Bodan

“They were crawling around and they got really close to each other, they were about to eat each other so I stopped looking.” Seon

“I was curious about what the little specks around them were.” Max

“When the water bears were fighting it was weird they were almost headbutting each other and then moving away.” Finn

“They looked like clear bear worms walking around.” Skye

“I saw they were pretty slow, it only wiggled around a tiny bit, it was probably conserving energy.” Annie

“You can see them move their legs to swim around, but not very fast.” Elsen

“Well some were very still but one was wiggling.” Connor

“They had green inside their bodies, maybe it’s their blood.” Oliver

“They are clear and could only move an inch in like a week.” Nate

“They don’t really move that much and they had green stuff inside.” Doanie

“They were see-through with little green bits in them, but the dead one I saw the green bits were gone, I bet the green bits are needed to live.” Parker

“The dead one was really creepy, I could see where the skin was ripped.” Everly

“The water bear was really still it was staying in one place.” Ever

“I saw a little water bear crawling around, I also saw a dead water bear and a line of bacteria, then I saw a really still water bear it wasn’t in a tun just really still.” Grace

“I tiny tiny microscopic water bears, they looked like they had slime on them and they had tiny claws.” Lennox

“It was clear with green in it, it was not moving much, there was one that had been eaten and you could see where it came apart.” Remi

“The dead one felt like all of the pieces of its body had come out.” Rileigh


McK & Mar