On March 20 this volcano in Iceland began erupting. It's forced 500 people in the area to evacuate their homes.
The eruption has produced a lot of ash, and that's because it's happening underneath a massive glacier.
Clouds of ash are lifted into the sky by huge plumes of steam that come from the eruption.
Low-energy lightning sometimes happens during eruptions, as tiny particles leave the volcanic vent at around 100 metres per second.
Experts say the last time this particular volcano erupted was between December 1821 and January 1823. We don't know how long the cloud of ash stayed around back then.
Volcanic ash can clog up and damage jet engines when it gets inside. The glass in the ash can also melt and block the ventilation holes.
Even though the ash is very fine, it can also damage the windscreen of an aeroplane, and because the cloud was in the atmosphere above the UK, the airports were closed.
F-16 jets like the ones in the this picture flew into the volcanic ash and reported some damage to their engines.
With airports across the UK closed, 150,000 British tourists were stranded around the world.
These special sensors were attached to the bottom of a German plane and used to test out the levels of volcanic ash in the air.
After six days of travel problems for lots of stranded British tourists, planes were finally allowed to fly again...
... and these passengers finally made it home.
Finn and Greta are in New York waiting for their dad to come through the arrival gates after he was stranded in Europe.
Here a farmer in Iceland holds some of the ash that fell from the air around his farm.
A helicopter landed on the glacier above the volcano to take some spectacular photos of the eruption.
These horses look like they haven't even noticed the huge ash cloud behind them!
This is a photo of the volcanic eruption in Iceland taken from a satellite in space.