Earth has been struck by the strongest solar storm since 2003
These storms are expected to continue through the weekend and possibly into next week
On Saturday night, they were visible in several parts of the world
Northern lights illuminated the night sky over Vienna during a geomagnetic storm
More CMEs are expected to pummel the planet in the coming days
G4s are the second-strongest type of solar storm
They've been known to cause radio blackouts and power-grid outages
The aurora borealis is typically contained in the uppermost region of the Northern Hemisphere
These were some of the storm visuals that were seen all over Earth