Credit: NASA/SDO/Goddard Scientific Visualization Studio
Rain is a common phenomenon on Earth. There is a similar phenomenon on the Sun, called coronal rain. It is related to the coronal heating and magnetic field, and plays a fundamental role in the mass cycle between the hot, tenuous corona and the cool, dense chromosphere.
Coronal rain usually takes place in post-flare loops and the non-flaring active region coronal loops. It is generally classified into two categories: flare-driven and quiescent coronal rain, depending on its relation to the flare. Both kinds of coronal rain form along structures that are magnetically closed.