What to know about the massive sunspot facing Earth again

Guilty? A geomagnetic storm is triggered by high-energy particles and magnetism ejected from a sunspot — a bruise-like discoloration on the Sun’s surface. The same sunspot cluster that had been hidden behind the Sun for weeks is now hurtling toward Earth again.

As the sunspot moves from left to right across the solar disk, a variety of geomagnetic storms are likely to form over the next two weeks or so. (It takes about 27 days to orbit the Sun once.) Another serious geomagnetic storm is unlikely in the near future, but moderate to severe geomagnetic storms are unlikely if a solar flare leaves a favorable sunspot. cluster.

This is technically the third time this sunspot cluster has faced Earth. It headed towards us for the first half of May, then returned towards the end of the month and early June. Now Earth is back in the line of fire.

Each time a sunspot cluster returns to the side of the Sun facing Earth, it is assigned a new number. In May, it was “Active Area 3664.” Then the 3697. Now it’s the AR3723 – and it explodes with magnetism.

On Sunday, for example, AR3723 spat out M-class sunlight. It is the second highest tier in the scale (it is A, B, C, M and X, X-class combustion being the largest). A pulse of radiation helped ionize Earth’s upper atmosphere, cA shortwave radio blackout was reported Over the Atlantic for several hours. And the AR3723 is spitting out more magnetic hiccups in the coming days and weeks.

Solar flares are intense bursts of high-energy particles and electrons that race through space at nearly the speed of light. They appear as intense bursts of light in the sun. Slow-moving shock waves of magnetism, called coronal mass ejections (CMEs), sometimes follow; They barrel through space like interstellar tsunamis. When a CME hits Earth, its perturbed magnetism interacts with Earth’s magnetic field, producing episodes of northern (and southern) lights.

It’s too soon to know what the AR3723 has in store.

It will take another day for the observation satellites to orbit within a better view, which will help scientists at the Space Weather Prediction Center in Boulder, Colo., better detect its magnetic system. From there, scientists can make probabilistic predictions — for example, the odds of an M-class or X-class solar flare within a given timeframe. These flares send high-energy particles toward Earth, leading to shortwave radio blackouts on the sunlit side of the planet.

The collection of sunspots is much smaller than before. But its magnetic structure is still strong enough to spit out strong flares. The Space Weather Forecast Center noted that AR3723 was “a highly magnetically complex point group” but had not evolved much over the past day or so.