GOODBYE SUNSPOT AR2736: Active sunspot AR2736, which hurled a CME toward Earth on March 20th, is about to leave the face of the sun. NASA’s Solar Dynamics Observatory took this extreme ultraviolet picture of the sunspot’s seething magnetic canopy tipping over the sun’s western limb on March 23th:
By Monday or Tuesday, AR2736 will vanish as it begins a 2-week trip around the farside of the sun.
Meanwhile, the sunspot still poses a threat to Earth even though it is no longer directly facing our planet. In fact, in a way, the sunspot poses a greater threat while it is near the edge of the sun. As the sun rotates, the sun’s magnetic field spirals out into the solar system like water flowing from a lawn sprinkler:
Because of the sweep of this spiral, Earth is well connected, magnetically speaking, to the edge of the sun. If AR2736 flares while it is there, the ejecta could be funneled back to Earth, potentially causing a solar radiaton storm.