The Sun belched out an ordinary solar flare five days ago on April 2nd. Most of us didn’t notice; solar flares are an ordinary occurrence, taking place anywhere from fifty to a thousand times per year depending on which part of the 11-year solar cycle we happen to be in. But the sheer size of these things, and the power of the Sun, can be frightening.
This is what a solar flare looks like:
And this is how big a middling-to-large solar flare is:
So it’s quite understandable that people might get worried. What works to our advantage is that:
- We’re about 93 million miles away from the surface of the Sun, so we’re never going to get the full undiluted brunt of a solar flare, and
- Our atmosphere protects us from getting roasted or irradiated by the parts of a solar flare that do head our way.
The geomagnetic storms solar flares cause can lead to regional blackouts, but solar flares of this severity are extremely rare.
Solar flares can potentially be hazardous to people and equipment in space and the upper atmosphere that aren’t under our atmosphere’s protection, and there’s reason to worry that a severe solar flare might destroy Earth’s satellite network—but this hasn’t happened yet, and it might never happen.
There’s also some evidence that solar flares actually help us, or at least those of us who aren’t already under the protection of Earth’s atmosphere. We’ve known since the 1930s that increased solar storm activity can deflect cosmic waves away from Earth (a phenomenon known as the Forbush effect); since all astronauts suffer some degree of brain damage and increased cancer risk as a result of these waves, normal solar flares actually make space safer for these astronauts than it would otherwise be.