How do the Northern Lights happen?
The Northern Lights are seen on Earth as spectacular splashes of colour in the night sky.
On Thursday experts say amateur star-gazers have the best chance in years of seeing them in all their glory.
The powerful rays can interfere with airline navigation systems, satellites and even NASA space crews - so they all had to be on high alert.
But if you're wondering what causes the night sky to glow, check out Leah's report to find out more...