When a camera is peppered by cosmic rays, the blips can appear in images.
Sometimes, high-energy cosmic rays can hit a camera as it is observing the universe. These can be from distant exotic sources, such as a supernova, or they can be randomly emitted from near to the camera lens.
Either way, the provide a sharp energy jolt to the camera, producing a tiny, white point in the image. These points can be seen by zooming in and looking closely at this image.