Ball lightning is described as shining spherical objects floating around or hovering above the ground. Most of the eye-witness accounts describe this enigmatic phenomenon as balls of fire or electricity. Despite plenty of evidence that exists, scientists are not any closer to figuring it out, and we see more and more wild speculations about these mysterious spheres of light. The internet is full of ball lightning photos believed to be real. However, most of them are manipulated images. What causes ball lightning? What is ball lightning? This is our pick of the most mind-boggling facts about ball lightning. Let's unriddle at least some of the riddles.

Amazing facts about ball lightning:

• There is no accepted theory for what causes it or what it is made of (there are over 400 existing hypotheses that describe the nature of ball lightning). One of the theories suggests that these balls of fire consist of electrons and force-activated ions. Some scientists agree that the origin of this phenomenon is sustained by electromagnetic waves generated when the Earth's crust fractures. When the Earth's surface is shaking during an earthquake or minor shocks, these flows of electromagnetic waves soar into the air giving rise to luminescent spheres. Due to the nature of this rare phenomenon having a lifetime of a few seconds, scientists have not succeeded in making extensive observations of these luminous spheres or in studying their properties.
• Ball lightning is common during thunderstorms. At other times, its causes have no relation to weather conditions.
• All attempts to produce ball lightning in the lab proved to be fruitless: though some motley crews of scientists could bring luminous objects to life, none of them could re-create the original nature of these objects. The thing is ball lightning looks like plasma bubbles that can't last long in lab conditions.
• A "typical" ball lighting is the size of a cabbage head. There were rare eye-witnesses saying the hovering objects varied from several millimeters to few meters in diameter. Ball lightning can take different forms: it can be round, pear-shaped, circular, ellipsoid, to name just a few.

• According to the research made by Alexander Grigoriev, a scientist from the city of Yaroslavl, Russia, ball lightning lasts for seconds to hours and vanishes following no particular pattern: either silently or with a blast, disappearing when striking the ground or hitting any type of conductor.

• Ball lightning emits light: sometimes dim, sometimes very intense. Ball lighting can travel at speed ranging from a few centimeters per minute to tens of meters per second.

• These floating spheres can range in color from white to yellow to green, or be even translucent.

• Information about the dangers caused by ball lightning varies enormously: while some witnesses struck by the sphere say they have not suffered any burns, others claim they saw ball lightning setting a haystack alight or even killed people.

• Most commonly, ball lightning zips around 1.5 meters above the ground. Still further, it can go several kilometers up from the ground.

• In 1963, ball lightning passed through a US passenger aircraft and vanished instantly not hurting anyone aboard or causing damage to the plane.

• Medveditsk ridge (Russia) located at the border of the Saratov and Volgograd regions is considered to be an anomaly site with the biggest number of ball lightning occurrences across the globe.