S1, E4: Our ancestors thought the sky was flat, but we now know it as a place of infinite depth. Only Hubble can make the jump across those huge distances with stunning clarity. This is an outward-bound journey from “here to infinity” showing all the scales where Hubble operates, from the solar system to the most remote reaches of the cosmos. Etched in Time – Hubble not only looks out into space, it looks back in time. The further light travels to reach the telescope the further back in time we see the object that emitted the light. Solar system objects are seen minutes to hours in the past, and the galaxies millions to billions of years in the past. With the long exposure Ultra Deep Field, Hubble can actually look to the time when the galaxies were still assembling. It’s a violent process that carries on today as massive galaxies collide. These images also foreshadow the fate of our own galaxy, which is even now moving towards an inevitable collision with its nearest neighbour.