Natasha JayJul 4

A NASA astronaut has captured an electrifying image of Earth from space, featuring a gigantic, jellyfish-shaped "sprite" of red lightning shooting upwards above a thunderstorm in North America. The rare phenomenon is still poorly understood, despite being studied for more than 30 years.

Image credit: NASA/ISS/Nichole Ayers

https://www.livescience.com/planet-earth/weather/astronaut-snaps-giant-red-jellyfish-sprite-over-north-america-during-upward-shooting-lightning-event

#NASA #Space

Show threadJustin DerrickJul 5
@Natasha_Jay Any idea what part they don't understand? We've had neon tubes for a hundred years already, and we know that high-energy particles is what gives us auroras...
Show threadgnarf
@JustinDerrick @Natasha_Jay We don't even fully understand how regular lightning works. We only really began understanding the charging mechanisms in the 2010s and it's still an open question as to what exactly triggers the initiation of the lightning strike.
Jul 5 at 8:08amWeb
Show threadConfused Middle Aged DadJul 5
@gnarf @JustinDerrick @Natasha_Jay true for many areas of electrostatics. For everything that we do know there are still some fundamentals that are still being worked on
Show threadJustin DerrickJul 5

@gnarf @Natasha_Jay I'm no physics major, but isn't it simply when the difference in electrical charges between the earth and sky/cloud exceeds the electrical resistance of the air? Or is there something extra I'm missing?

It's the same thing for a static shock -- if I scruff my feet on shag carpet and I touch something conductive and grounded, the spark and snap is the result of the surplus of electrons bridging the last few millimetres. The scale is just... way bigger.

Show threadgnarfJul 5
@JustinDerrick @Natasha_Jay You'd think that but if you calculate the necessary charge for bridging the gap it's about ten times higher than what's present in common thunder clouds.
Show threadArthur van der HargJul 6
@JustinDerrick @gnarf @Natasha_Jay Yes, but your description is kinda like saying that cars move because the power supplied by the engine exceeds the friction forces working on the car. It’s not untrue, but it’s lacking a bit of detail.
Show threadjoostetoJul 6

@JustinDerrick @gnarf @Natasha_Jay
That's the easy part.
The difficult part: *why* do the differences in charge build up?

Yes, that also applies to static electricity in your shag carpet. The Tribo electric effect that causes it isn't fully understood either.

"While many aspects of the triboelectric effect are now understood and extensively documented, significant disagreements remain in the current literature about the underlying details."

https://en.wikipedia.org/wiki/Triboelectric_effect

Triboelectric effect - Wikipedia