The Heliospheric Imager for the NASA STEREO Mission
Part of the SECCHI Consortium
This image, from the RAL Space-led HI-2 camera on STEREO-A, shows the result of a micrometeor impact on the spacecraft on May 6, 2016.
A small dust particle hitting the thermal blanket sends out a spray of debris.
Although such impacts are common, in this case the camera was returning short time-scale exposures so the signature is clearer than usual.
Even with an exposure time of 50 seconds, ejected particles show up as streaks.
Such signatures have been used to determine dust distributions at 1 AU.