Plasma is the fourth state of matter (the other states being solid, liquid, and gas). It is formed when electrons are stripped away from atoms and a mix of free electrons and the resulting ions exist together. Plasma is found in stars, which makes it actually the most common state of matter in the universe. But plasma is also found in the solar winds that blow out from the Sun and collide with the magnetosphere. Some plasma radiation makes its way into the ionosphere, too. Lightning is also a form of plasma.