Micrometeor Impact on STEREO Spacecraft

This image from the SECCHI HI2 telescope on STEREO Ahead shows the result of a micrometeor impact on the spacecraft that occurred on May 6, 2016. A small dust particle hit the thermal blanket at high velocity near the telescope, and sent out a spray of tiny debris particles. Such events are actually very common, but they're usually not seen so clearly, because the normal data are a combination of many images covering a long time frame. However, in this case, the telescope was in a rare single-image mode, and was lucky enough to catch the event in one of the images. Even in this single image, the exposure time was 50 seconds, so the ejected blanket particles show up as long streaks.