Solar flares are among the most terrifying events in the solar system. These are colossal explosions of energy, the biggest of which can blast out as much as 10% of the Sun's total energy — the equivalent of detonating billions of one-megaton nuclear bombs.
They do more than simply explode on soul-crushing scales. They also send out high-energy gamma rays and a wave of subatomic particles that can damage satellites and partially ionize the Earth's atmosphere, causing telecommunications issues and even power outages.
These are a serious threat to our space-faring and technology-based civilization. Predicting them is difficult, so the more we understand them the better.
In the 1990s it was found that besides sending energy into space, they also produce a tremendous pulse of energy downward, into the Sun. This can get converted to acoustic waves, literally sound waves that travel through the Sun's upper layer, and these can be seen as circular ripples in the Sun's surface moving outward, away from the flare.
How this works exactly, though, has been a mystery for two decades. New observations, though, have revealed a surprise: The source of these waves can actually come from deep inside the Sun, as much as ...