If you’re teaching students about the Solar System, you’ll likely spend a good deal of time on Jupiter, the largest of the planets. Any discussion of Jupiter must, of course, include the Great Red Spot, the gargantuan, anticyclonic storm that has been raging on the planet for at least as long as humans have been able to see its surface through telescopes.
Like any large storm, the Great Red Spot (GRS) is somewhat unpredictable. It’s counterclockwise rotation is violent and highly variable—it often rotates at a faster or slower rate than the rest of the planet’s atmosphere. What makes the GRS move the way it does?
DIY Mightiest Storm in the Solar System
For this fun and easy demonstration, you’ll need a wide-mouthed one gallon jar (preferably glass), water, a tea bag, and a stirring utensil such as a pencil. (I’m a poet and I am fully aware of that fact.)
First, fill the jar almost to the top with water. Then, rip or cut open the tea bag and pour the loose leaves into the water. Stir the water with your pencil or other utensil, quickly twirling a small circle in the middle of the water. Keep stirring until the tea leaves start to group together and gravitate toward the spinning center of the water.
Unless the water vortex you’ve created is large enough to contain roughly three planet Earths, it’s smaller than the real thing. But it will likely be more than sufficient for our purposes, so, well done!
What is This Science of Which You Speak?
As students can observe, the movement of the water from the outer edge of the jar into the vortex, and the vortex’s downward (relative to the surface of the water) spiral create a cavity in the center of the jar. From what scientists can observe, the red in the Great Red Spot is made up of particles of unknown origin, in much the same way that your DIY GRS got its color from tea leaves.
And, in much the same way that the tea leaves were brought together by the swirling motion of the water in the jar, the red particles of Jupiter are brought together in a great spot by a swirling vortex in the planet’s atmosphere.
- Janice VanCleave’s 200 Gooey, Slippery, Slimy, Weird and Fun Science Experiments, Janice VanCleave, 1992. ISBN 978-0471579212