What is spherical lightning? What's the harm?

Spherical lightning, commonly known as rolling thunder, is a spherical lightning ball. This is a real physical phenomenon, not an energy cannon of science fiction or comic series. This phenomenon was recorded as early as 1838. Scientists have studied it for 160 years and published thousands of related reports and more than 2,000 scientific papers. However, we still have no reasonable explanation for this phenomenon, but it is not credible to say that it can cross any object.