Right now you're hurtling around the sun at 64,000 miles an hour (100,000 kms an hour). In the next year you'll travel 584 million miles, to end up back where you started.
Presenters Kate Humble and Dr Helen Czerski follow the Earth's voyage around the sun for one complete orbit, to witness the astonishing consequences this journey has for us all.
In this final episode we complete our journey, travelling back from the March equinox to the end of June. Kate Humble is in the Arctic at a place where spring arrives with a bang, whilst Helen Czerski chases a tornado to show how the earth's angle of tilt creates the most extreme weather on earth.