Plasma Rain On April 19, AIA observed one of the largest prominence eruptions in years. The huge structure erupts, but a great deal of the plasma (hundreds of millions of tons) is unable to escape the gravitational pull of the Sun and falls back down as "plasma rain." As the rain impacts the surface, bright flashes can be seen as the momentum is absorbed on impact. SDO is the first observatory to capture both the rain and the impacts, allowing us to learn a great deal from observations like this.