For stability, the cloud must be in hydrostatic equilibrium, which in case of a spherical cloud translates to:

This solution describes a spherical cloud of dust (finite or infinite) that is expanding or collapsing under gravity.

In modern quantum mechanics, the electron in hydrogen is a spherical cloud of probability which grows denser near the nucleus.

Are all solar systems embedded in a vast spherical cloud of comets?

The Debye-Hückel theory was based on the assumption that each ion was surrounded by a spherical "cloud" made up of ions of the opposite charge.

Water vapor in the air condensed as a result of a Prandtl-Glauert singularity, making a spherical cloud that marked the location of the shock wave.

You can make out the halo, the spherical cloud around the main disc: very ancient, stable stars.

The nebula forms a roughly spherical cloud that peaks in density near the core.

Earth began falling on me soon after the shock-wave had passed and there was a spherical cloud of chalk billowing round the crater the plane had made.

This thing you've got here seems, on the other hand, to be just one single spherical cloud.