Solar activity goes through cycles. The main one is about 11 years long and its maximum is marked by powerful eruptions of electromagnetic radiation known as solar flares, as well as releases of plasma known as coronal mass ejections. The most powerful known flare happened in 1859 and led to telegraph stations catching fire across the US, and Northern and Southern Lights becoming visible in the tropics.
Host Dr Alfredo Carpineti spoke with Dr Ryan French, astronomer at the National Solar Observatory and author of The Sun: Beginner's Guide to Our Local Star, to find out about solar flares and what would happen if a massive one took place today.
You can listen to this episode and subscribe to the podcast on all your favorite podcast apps: Apple Podcast, Spotify, Google Podcast, Podbean, Amazon Music, and more. A transcript of the conversation is available here.



![An artist’s concept looks down into the core of the galaxy M87, which is just left of centre and appears as a large blue dot. A bright blue-white, narrow and linear jet of plasma transects the illustration from centre left to upper right. It begins at the source of the jet, the galaxy’s black hole, which is surrounded by a blue spiral of material. At lower right is a red giant star that is far from the black hole and close to the viewer. A bridge of glowing gas links the star to a smaller white dwarf star companion immediately to its left. Engorged with infalling hydrogen from the red giant star, the smaller star exploded in a blue-white flash, which looks like numerous diffraction spikes emitted in all directions. Thousands of stars are in the background.]](https://assets.iflscience.com/assets/articleNo/76155/aImg/79193/jet-m.jpg)
