NASA - National Aeronautics and Space Administration

Febo Donut

Every particle is its own little zoo, with its own unique mixture of component members. Shown above is a portion of a comet particle from Comet Wild 2 using an electron microscope. The light gray doughnut surrounding the X consists of carbon-rich organic material. The scale bar at the bottom of the figure is 0.1 microns long.

Image Credit: Matrajt et al. 2008