Apr 26, 2017

What causes the Sun's eruptions — big or small


Plasma eruptions from the Sun's surface — from small bursts to gigantic eruptions that can cause spectacular auroras on Earth — are all part of the same process and have the same underlying mechanism, a new study in Nature shows.

Why this matters: Electromagnetic radiation from the sun can cause interference with radio and satellite transmissions. The high-energy, charged particles from the sun's eruptions also can endanger astronauts in space (one of the challenges to traveling to places like Mars). Understanding the true nature of the plasma eruptions across the entire spectrum will potentially allow scientists to mitigate risks.

A closer look at the Sun: There are two very different types of hot gas eruptions from the Sun's blazingly hot surface: relatively small bursts of plasma (coronal jets) and huge clouds of plasma (coronal mass ejections) that explode off into space at very high speeds. Because the eruptions are on such vastly different scales, scientists thought they were driven by different processes.

Using 3d computer simulations, scientists from NASA's Goddard Space Center and Durham University in the UK were able to show that the Sun's eruptions are theoretically part of the same process. When large regions of dense, cool gas called filaments become unstable or stressed, they break through the magnetic field that suspends them above the Sun's surface and trigger small and large ejections.

Go deeper