  Sweeping beams of light can cast spots moving with superluminal speeds across
scattering surfaces. Such faster-than-light speeds are well-known phenomena
that do not violate special relativity. It is shown here that under certain
circumstances, superluminal spot pair creation and annihilation events can
occur that provide unique information to observers. These spot pair events are
{\it not} particle pair events -- they are the sudden creation or annihilation
of a pair of relatively illuminated spots on a scattering surface. Real spot
pair illumination events occur unambiguously on the scattering surface when
spot speeds diverge, while virtual spot pair events are observer dependent and
perceived only when real spot radial speeds cross the speed of light.
Specifically, a virtual spot pair creation event will be observed when a real
spot's speed toward the observer drops below $c$, while a virtual spot pair
annihilation event will be observed when a real spot's radial speed away from
the observer rises above $c$. Superluminal spot pair events might be found
angularly, photometrically, or polarimetrically, and might carry useful
geometry or distance information. Two example scenarios are briefly considered.
The first is a beam swept across a scattering spherical object, exemplified by
spots of light moving across Earth's Moon and pulsar companions. The second is
a beam swept across a scattering planar wall or linear filament, exemplified by
spots of light moving across variable nebulae including Hubble's Variable
Nebula. In local cases where the sweeping beam can be controlled and repeated,
a three-dimensional map of a target object can be constructed. Used
tomographically, this imaging technique is fundamentally different from lens
photography, radar, and conventional lidar.
