The Butterfly-Shaped Hole in the Sun
In September 2025, a striking feature appeared on the surface of the Sun that captured both scientific and public attention, a vast, butterfly-shaped coronal hole . While the poetic nickname reflects its unusual appearance, the phenomenon itself is a significant event in solar physics and space weather forecasting. Understanding what this means requires a closer look at the nature of coronal holes, the solar wind they generate, and their potential influence on Earth. Coronal Holes and Their Characteristics Coronal holes are regions in the Sun’s outer atmosphere, or corona, where the Sun’s magnetic field is not closed but extends outward into interplanetary space. This open configuration allows charged particles and plasma to escape more freely, creating fast streams of solar wind. These areas appear darker in extreme ultraviolet and X-ray imagery because they are cooler and less dense compared to the surrounding corona. Although coronal holes are a common feature of the solar cycle,...