A canyon-shaped hole in the sun's atmosphere is facing Earth and spewing solar wind in our direction. Estimated time of arrival February 5th or 6th. Extreme ultraviolet images from NASA's Solar Dynamics Observatory show the structure, which stretches more than 750,000 km from the Sun's south pole to the equator. The emerging stream of solar wind will reach Earth on Feb. 5th or 6th, bringing a chance of G1-class geomagnetic storms. Coronal holes are a primary form of solar activity during Solar Minimum, which is underway now. Arctic sky watchers should be alert for auroras when the gaseous material arrives.