Episode 1 begins the journey of the earth around the sun by looking at Earth's January to March equinox, experiencing spectacular weather and the sun at perigee. Kate Humble gets closer to the sun than she has ever been before, whilst Helen Czerski visits a place that gets some of the biggest and fastest snowstorms on earth.

Episode 2 looks at Earth's spin by traveling from July to the December solstice, experiencing spectacular weather and the largest tides on earth. To show how the earth's orbit affects our lives, Helen Czerski jumps out of an airplane and Kate Humble briefly becomes the fastest driver on earth.

Episode 3 completes the journey of the Earth around the sun 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, while Helen Czerski chases a tornado to show how the earth's angle of tilt creates the most extreme weather on earth.