It’s taken more than ten years, but scientists have at last proved that tsunamis happen on the sun as well as in the ocean.

The mystery first started in 1997, when scientists witnessed something known as a coronal mass ejection (CME) on the sun. This is a huge bubble of gas and magnetic energy that bursts out of the sun.

After this particular CME, researchers saw a wave travelling away, but weren’t sure if it was real or a shadow from the blast. Many similar events were seen over the years.

In February this year, NASA’s two STEREO craft (Solar Terrestrial Relations Observatory) saw a CME that threw a billion tonnes of gas into space. At the time, the two craft were separated by an angle of 90° to the sun, which was ideal for getting a good view.

The CME caused a tsunami, or MHD wave, that reached 100,000km high and travelled at 250km per second. Scientists estimated that it had as much energy as more than two billion tonnes of TNT!