In 1981, the Voyager 2 space probe took intriguing images of Saturn’s rings as it passed by the giant planet on its way to Uranus.
The images showed what looked like ghostly “spokes” moving on the rings, much like the spokes of a bicycle wheel as it turns. After some head-scratching, scientists realized that the Saturnian spokes most likely were tiny specks of dust moving around the rings due to electric and magnetic forces. These forces result from electrically charged gases known as plasma.
Even though you might not realize it based on our daily experiences, researchers think that 99 percent of the matter in our universe is in a plasma state. Many processes that occur in the universe are due in part to the presence of plasma.
Here on Earth, industry uses techniques that involve manipulating these ionized gases for microchip production, as well as for welding materials such as aluminum. Research facilities study plasma in hope of hitting on an efficient nuclear fusion process for energy production. In all these instances micron-size dust is present – which can be a good or a bad thing, depending.
The presence of dust in plasma makes it tricky to study them in a laboratory setting. Here at Baylor University’s Center for Astrophysics, Space Physics and Engineering Research (CASPER), we’ve built a sophisticated experimental facility to investigate these dusty plasma systems. We hope to answer fundamental questions related to dust-plasma interactions both on Earth and in space, in the process advancing our understanding of physics and astrophysics. Our investigations will allow us to untangle issues like the role of dust buildup in super-high-speed crashes in space, the formation of planets, and even areas belonging to life sciences, such as double-helix molecular interaction.
Solid swimmers in an electrical sea
Dusty plasma, also called complex plasma, contains small, solid particles distributed throughout the ionized gas. These particles can have the shape of a sphere, a rod or an irregular “pancake.” The reason dusty plasma are very interesting, and even technologically valuable, comes down to the fact that the dust particles themselves can become electrically charged.