A gigantic sunspot has swelled to twice Earth's size, doubling its diameter in 24 hours, and it's pointed right at us.
Sunspots are natural phenomena for stars all around the universe. They are dark spots on their surface created by areas of intense magnetic flux interfering with the convection processes that bring superheated material up from the Sun's core.
The fact that these are normal, natural phenomena, however, does nothing to reduce the violence of their conclusion. As the electromagnetic conditions that create sunspots build up, they can reach a critical point upon which they snap. This snap is associated with a huge release of energy that manifests as solar flares. Such flares release huge levels of radiation and jets of solar material called coronal mass ejections (CMEs) into space.
When a CME happens to be aimed toward Earth, however, it can cause quite some issues on the surface.
Enormous potential issue
"Yesterday, sunspot AR3038 was big. Today, it's enormous. The fast-growing sunspot has doubled in size in only 24 hours," Spaceweather.com reported. "AR3038 has an unstable 'beta-gamma' magnetic field that harbors energy for M-class [medium-sized] solar flares, and it is directly facing Earth."
Right now, AR3038 is around 2.5 times the size of Earth, Spaceweather.com adds. A sunspot's size is a good indicator of the amount of energy it contains and that can be released as a CME.
If a solar flare comes into contact with Earth's upper atmosphere, the X-rays and ultraviolet radiation it carries will ionize a lot of gas atoms at this level. While that doesn't really affect us directly, it does wreak havoc on our long-range communications.
Radio waves travel in straight lines from their sender. Since the Earth is round, this means that they eventually start traveling toward outer space. But the upper layers of the atmosphere bounce radio waves back down towards the planet, making long-range communications possible. If sufficiently ionized, however, the upper atmosphere no longer reflects radio waves. As such, solar flares can produce radio blackouts over vast areas of the Earth at a time while active. The severity of a blackout is measured on a scale ranging from R1 (Minor) to R5 (Extreme) disruption in communications.
Due to traveling at the speed of light, solar flares only take around 8 minutes to reach Earth; as such, it's impossible to get any advanced warning that one is occurring.
That being said, they can cause disruption, but they do thankfully pass, and don't cause direct destruction. The harmful radiation contained by a flare cannot pass through our atmosphere to reach the surface. And they tend to only affect certain areas of the globe at a time. Two solar flares, for example, caused R3 backouts over the Atlantic Ocean, Australia, and Asia back in April and May. They only lasted a bit over one hour.
We know from past observations that if an Earth-facing sunspot forms near the Sun's equator (as AR3038 did), it takes around two weeks for it to travel far enough across the Sun's surface so that Earth is no longer in the way of any potential flare. AR3038 is currently slightly to the north of the solar equator and is halfway through the distance it needs to go for Earth to be outside of its flare.
Even if our planet doesn't move completely out of harm's way, AR3038 is most likely to produce an M-class flare; this is the most common type, which "generally cause brief radio blackouts that affect Earth's polar regions", according to the European Space Agency. Any physical material that the flare would release will also be repelled by the Earth's magnetic field, and generate geomagnetic storms. The most observable feature of such storms is the generation of aurora lights in the night sky.
The most powerful such event seen to date was (likely) the 1859 Carrington Event. This overloaded the global telegraph systems of that time and produced extremely bright auroras as far south as the Caribbean. Although these events are exceedingly rare, if one were to take place today, it could cause trillions of dollars in damage to the world's electrical and communications grids and lead to widespread blackouts.