# Would lightning strike a flying island?

Looking for someone with meteorology/physics knowledge to help with this one.

Let's say I've got an island that floats in the sky--nothing special, these are a staple of fantasy these days. For argument's sake lets put it at a reasonable elevation of about 7,000 feet.

Now, this is going to put it right in the middle of any cumulonimbus cloud that comes along. My understanding of lightning is a little shaky, but it seems like the island would be 'grounded' by virtue of being ground and therefore lightning might be attracted to it. Would people living on such a flying island have to worry about lightning storms? Would they have to worry more than people living on terra firma?

• HOW can you ground a floating fantasy island then?? Commented Aug 3, 2018 at 3:46
• Lightning can just as well occur between points above ground, and I actually believe that this is more common on Earth than lightning strikes that reach the ground. Lightning happens because the (electric) potential difference between two points exceeds the breakdown voltage of the medium; there is no requirement for this to involve any point on the ground.
– user
Commented Aug 3, 2018 at 6:20
• @TroubleIdeas If you have a new question, then go ahead and ask it. Make sure to show us that you've made some effort in answering it yourself first; How to write the perfect question has suggestions for how to write a question that is likely to be well received by the community. I'm not sure why it was felt that what you wrote is suggesting improvements or seeking clarification on the question; it seems to me to be a different, albeit related, question.
– user
Commented Aug 3, 2018 at 6:22
• Addendum: You cannot ground a floating island. Commented Aug 4, 2018 at 18:48

It can.

If the wind of the storm caused a big enough static charge on the island (or part of it), lightning would strike it to equalize the charge.

Lightning arcs from cloud to cloud for the same reason.

Or, a thin part of the island may just be in the way. Flying aircraft are sometimes hit by lightning. the aircraft is not the target but it happened to be in the way when the lightning arced. It can make a dime sized hole through the aircraft (better hope a person or fuel tank isn't in the way).

Short answers: Yes, and Yes.

Not only is there cloud to ground lightning, there is cloud to cloud lightning. Floating islands would be subject to both. And unfortunately, just because they are made of dirt, does not mean they are grounded. Lightning is just a massive static electrical charge, so they could (depending on their exact composition) generate lightning of their own that could zap other nearby things (eg, other islands or people flying too close).

• To expand on the "generating lighning of their own" - an example of a ground-to-sky lightning strike is positive lightning which is more dangerous than normal lightning, and accounts for about 1-in-20 of lightning strikes. Commented Aug 3, 2018 at 11:30

You also might have island to ground lightning (or ground to island). The lightning from cloud to island would likely be lighter, because the island isn't grounded and because you don't need as big of a charge differential to overcome shorter distances. So small but frequent bolts to equalize the charge. But then the island itself would have a distinct charge. Eventually, it could strike the ground with lightning. And those would be the big bolts.

It's also possible that the island might get hit by lightning from the clouds when high and strike the ground with lightning when lower. It depends on how your island moves. Is it always at the same altitude? Or constantly changing?

Incidentally, lightning is the answer to how clouds (and floating islands) ground themselves.