This spot on the sun is so big you can see it with no equipment (but use equipment anyway)


Don’t look now, but the sun has a big dot on it. Like, literally, don’t look. You could permanently damage your eyes.

At almost five times the diameter of Earth, sunspot AR3190 is an attention-seeking blob on the surface of our star — so big you can currently see it whenever the sun is shining. But don’t give into the temptation to gawk unless you have a pair of eclipse glasses or goggles, preferably ones certified by the International Standards Organization(Opens in a new window) (ISO). 

And by the way, it’s a good time to stock up on eclipse glasses because they tend to get expensive in the weeks before a solar eclipse, and there’s one coming on April 8.

So what’s the deal with this huge sunspot?

At the start of the current solar cycle — the sun’s roughly eleven-year pattern of only-somewhat-understood(Opens in a new window) magnetic phenomena  — astronomers predicted(Opens in a new window) that the peak year for solar activity such as sunspots would be 2025. It’s only 2023, and we’re experiencing extraordinary levels of solar activity, including impressive eruptions of plasma(Opens in a new window), and quite a few big spots — though none of the others are nearly as large as AR3190. Sunspots like this are unusual, but far from unheard of(Opens in a new window).

Does this sunspot pose any danger?

This sunspot probably poses no actual danger, but it does have a decent chance of, well, exploding.

When a sunspot this size explodes, one can expect a release of energy called a solar flare. Astronomers expect that AR3190 would produce an “X-class” flare, the most intense kind. X-class flares send things like radio waves, X-rays, and gamma rays out into space at the speed of light. When Earth gets hit by a strong flare, the results can be good things like beautiful auroras at northern and southern latitudes, but also radio blackouts, satellite damage, and power grid disruption.

A sunspot explosion can also be accompanied by a coronal mass ejection (CME), which is a relatively slower ejection of particles from the sun’s “corona” — its atmosphere, basically. CMEs also cause beautiful auroras and also have the capability to disrupt communications and knock out power.

But it’s anyone’s guess if any of this will happen before AR3190 rotates out of view — which will also reduce the potential for the ensuing activities to cause problems on Earth.