Image of the Day: sun, with a purplish hue

This ultraviolet image of the sun, courtesy of the NASA Solar Dynamics Observatory (SDO), is helping scientists better understand violent solar outbursts. These eruptions are sometimes so powerful they disrupt Earth's global positioning systems and electrical grids.

But what exactly is this showing us? Read on:

The purplish aura reveals high-arcing loops of 3.6-million-degree plasma that link sunspots and other magnetic areas on the surface; white lines illustrate computer calculations of how the magnetic areas connect.