cosmic rays

Kevin Palmer (@krp234) — Jun 17 This is a muon, aka a secondary cosmic ray. They often show up on long exposure images. But this is the longest one I've seen at 176 pixels wide [Embedded photo: night-sky long-exposure landscape photo over a canyon/river, with a magenta/purple aurora-like glow amid clouds and stars, greenish glow on the horizon. Inset zoomed panel shows a bright diagonal magenta-green streak identified as the muon track, with a line pointing to its location in the full image. Photo credit watermark: "Kevin Palmer Photography".]