Ages 8–12 · about 6 minutes

Glowing Balls That Hold Themselves Together

Can a glowing ball of hot gas really hold its own shape?

Do this first · Try this at home

A glow and its clues

Start with your hands. The reading makes far more sense afterwards.

You need: Paper and a pencil

Tick each step as you do it

Draw a glowing ball. Beside it, draw an imagined spectrum with three lines. Label both drawings imagined.
Write: the researchers measured light and found lines from soil elements. What does the picture alone leave out?
Add a question about how the glow gets energy or keeps its shape. Mark it as a question, not a measurement.

0 of 3 steps done

What should I notice?

Notice: A picture shows appearance; a measured spectrum adds information about material. Your pencil marks are not measurements and cannot identify real elements.

Now read on to find out why it happens.

The big idea

A glow's spectrum gives clues about its material; electric currents and magnetic fields can organize plasma.

plasma: A gas containing free electrons and ions that respond together to electric and magnetic fields.
ionization: Making an atom or molecule electrically charged, for example by removing an electron.
spectrum: Light separated by wavelength, showing a pattern that can help identify emitting material.
plasmoid: A localized plasma structure associated with magnetic fields, not necessarily a sphere.

In July 2012, Jianyong Cen, Ping Yuan and Simin Xue recorded a glowing ball after a lightning strike in China. Their instruments separated its light into a spectrum. The team reported the observation in 2014.

Lines in the spectrum matched silicon, iron and calcium, elements found in soil. That supports soil material taking part in this event. It does not, by itself, explain how the ball kept glowing or show that every ball has the same origin.

An imagined painted rural night scene shows a luminous ball above a rain puddle, with trees, hills and a distant storm. No people or animals are present. — An original painted illustration, not a photograph of the measured event. The bright arcs are decorative, not measured current paths or a spectrum.

Charged gas and magnetic fields

In plasma, some electrons are free to move among electrically charged atoms or molecules called ions. Neutral atoms can remain too. Ionization is not the same as breaking an atom's nucleus apart, and a plasma need not be extremely hot throughout.

Moving charges can form electric currents and make magnetic fields. Those fields can change the motion of charged particles. Under suitable conditions, this helps plasma form organized structures rather than simply spread out. It is not an automatic magnetic squeeze on every glowing gas.

What the laboratory shows

In his 1956 report, Winston H. Bostick described plasma structures called plasmoids and measured signals associated with their magnetic fields. He also photographed rings formed in an applied magnetic field. A plasmoid need not be a ball; its shape and lifetime depend on the conditions.

These experiments connect currents, fields and plasma shape. They do not establish that a natural ball of lightning is one of Bostick's laboratory rings.

Tiny marks, different explanations

Ken Shoulders described compact charged entities produced by electrical discharges. Graham K. Hubler's 2022 paper examines their reported photographs and marks on materials. He proposes that tiny portions of heated material can be expelled and produce such marks through mechanical and electromagnetic effects. This is an explanation to test, not a new measurement of natural ball lightning.

The useful questions are specific: what is emitting the light, where does its energy come from, and what keeps its shape? Spectra, timing and electrical measurements can help separate the answers. Our paper activity uses drawings, not sparks or storms.