The balls of light that are often called UFOs might be just plasma.
Lightning hitting the ground causes the earth to be positively charged by the ejection of electrons. The earth is converted to plasma comprising magnesium, carbon, silicon and iron and thrown into the air where it flies around. As it moves in the air the electrons are gradually restored and light is the result.
There is a theory that plasma containing some magnesium are this has a very bright light when it burns.