Fire takes a different form away from the force of gravity. Now a kaleidoscopic shot of heptane combustion from the International Space Station shows the unusual way fuels burn in weak gravity.

As part of an experiment assessing combustion and fire suppressants in space, a 3-millimetre-wide drop of heptane fuel was ignited and filmed as it transformed into soot. A bright backlight illuminates the combustion process. Using different image-processing techniques, the researchers can quantify the amount of soot at each frame in the film.


In this composite false-colour image, the yellow structure in the centre marks the path of the heptane drop, shrinking as it burns. Green soot structures collect near the fuel, the larger particles eventually streaming out like the embers of a firework.

(Image: NASA)

This post originally appeared on New Scientist.