The G1 storm could cause power grid damage, disrupt satellites and disrupt animal migration, according to the US National Oceanic and Atmospheric Administration. However, they are relatively minor – with much more dramatic effects possible during geomagnetic storms. The organization said such conditions were “likely” on Wednesday, August 3, as a result of a hole in our star. Coronal holes appear as dark spots in UV and X-ray images of the Sun. They are cooler and less dense parts of our star, which means the solar wind can more easily escape into space. This means that fast streams of solar wind can be shot out of the Sun – and can be directed towards Earth. Such a current will look into our atmosphere, leading to possible effects both in the space directly above us and below the Earth. Coronal holes can form at any time, although more occur during solar minimum. We are currently moving out of such a time and towards solar maximum, where the Sun’s activity increases in intensity, which is expected to reach sometime around 2025. As that time approaches, scientists expect space weather to have a more regular and potentially more devastating impact on life on Earth. Scientists have repeatedly warned that human civilization should do more to protect against catastrophic solar weather before more intense events arrive. NOAA’s solar weather scale starts at G1, which is what Wednesday’s storm is expected to be, which is listed as “minor.” It goes up to G5 – an “extreme” geomagnetic storm – where widespread power system problems are expected, spacecraft could be disoriented and radio signals and satellite navigation could be temporarily blocked. However, such extreme solar storms are relatively rare. Extreme solar storms of this kind occur only about four days in each of the Sun’s 11-year cycles.
