If your students know Jimmy crack corn about our solar system, they know Jupiter, Mightiest of Planets™. But are your junior astronomers aware that Jupiter’s gaseous atmosphere is subject to nigh-constant lightning strikes? It’s true… but why?! Well, here’s a fun and easy Demo Science science demo that will help you explain to those smelly little buggers why Jupiter is always a-jumpin’.
Static Electricity is the Best Electricity
For this one, you’ll a mere handful of supplies. One: a roughly 2” by 8” strip of thin plastic (any kind of plastic will work, but for budgetary reasons you’ll probably want to stick with something like an el cheapo report cover sleeve thing and not, say, a slab of Vespel). Two: a 100% wool cloth. Three: that’s it.
Turn out the lights in your classroom, and ask your students to observe closely—natch. Hold one end of your plastic strip and wrap the wool cloth around it. Hold the plastic tightly in the wool—but not too tightly. Quickly pull the plastic through the wool. Repeat that process as quickly as possible, about five to seventy times. What do your students see as the plastic moves across the cloth?
A Handful of Shazam!
If everything went off as it should, students should have spotted a sparkly, bluish light betwixt the folds of the woolen cloth as the plastic passed through it. ¿Por que? It’s electrons on the move, homeboy!
With each stroke, electrons transfer between the plastic and the wool. As you’re doing your thing in this experiment, some of the electrons from the wool jump ship to the plastic. This causes the wool to become positively charged, and the plastic negatively charged. Continued wool-on-plastic action makes the electrons jump from the plastic back to the wool, creating static sparks.
In Jupiter, Mightiest of Planet™’s atmosphere, this general process happens nonstop. Winds on the gas giant blow up to 800 miles per hour, which causes the molecules in the atmosphere to vigorously rub against each other literally all the time, making electrons jump back and forth and back again, which in turn causes gargantuan static sparks—lightning strikes.
And no, Kevin, the atmosphere on Jupiter is not made of plastic and wool.
Photo credit: Foter.com