The ominous black square on the surface of the sun isn't a portal to another dimension. It's a coronal hole, a depressingly mundane name for a patch of cooler and darker corona. While the usual bright glow is hot, bright plasma captured by the magnetic field, a coronal hole is a gap in the magnetic field.
NASA's Solar and Heliospheric Observatory (SOHO) has captured images of an unusually large coronal hole on the surface of the Sun. At one point, it was so large that it covered nearly a quarter of the Sun's visible disk — a distance equivalent to 50 Earths placed side-by-side.
This image, snapped by the Japanese probe Hinode on February 1, looks way more terrifying than it actually is. Most of the top half of the Sun seems to have fallen into a massive black hole, but it's not quite that dramatic. It's actually a coronal hole, a gigantic opening that allows the Sun to vent excess gas.…