What you are looking at is the telltale sign of a on your double-pane (insulated glass) window.
You wake up on a chilly morning, look out your living room window, and see it: a thick layer of fog trapped between the two panes of glass. You wipe the inside. Nothing. You scrub the outside. Nothing. broken seal on double pane window
If left for years, the moisture reacts with the glass and hard water minerals. Eventually, the fog turns into hard white streaks that look like scratches. At that point, cleaning is impossible, and the glass must be replaced. Can you fix it? (Spoiler: Don’t drill the glass) If you search YouTube, you will find "hacks" for fixing a broken seal—drilling a tiny hole in the glass to let the moisture out and inserting a one-way valve. What you are looking at is the telltale