At day 4 we’re nearly half way through the event. Hope you’re all chatting, asking and voting!

Today’s highlights in the Extreme Speed Zone:

• Volcanoes are very very hot…

Precisely how hot is it in a volcano?

• A great explanation from Claire:

What is a worm hole and how does it work?

• And moon movement and lightning…

Other than its orbit, does the moon move?

If lightning produces so much energy, couldn’t mankind harness it?