Summary Our solar system is home to a vast array of mysterious wanderers. Lonely piles of rock and ice. These are the asteroids and comets.

Some of them are only tens of metres across. Others are bigger continents, like lost moons.

After occupying their usual habitats for billions of years, they can be flung away to a new fate by distant interactions with the planets. Sometimes they are ejected from the solar system, and sometimes they are on a collision course with Earth. Comets and asteroids have caused multiple extinctions on our home planet. Pretty terrifying stuff. But they are also bringers of life.

Many of these ancient celestial objects have been wandering in our midst, since before the solar system formed. After the violent formation of the Earth, these cosmic couriers would have delivered water and organic compounds to our planet. We owe our existence to them.

This film is the extraordinary story of how we have actually sent spacecraft to visit these wandering worlds. Audiences will be staggered by the audacity of sending robotic emissaries billions of kilometres into the dark unknown to visit these places. Our spacecraft have touched, landed upon and sampled these asteroids and comets. Doing so is among the most challenging endeavours that Humankind has ever undertaken.

This film has stories of immense determination and anguish, relayed by the scientists and engineers from the front line of space exploration. Tales of catastrophic failure and miraculous moments of snatching success from the jaws of disaster. The triumph and elation in these stories has no equal in space exploration.

A journey into the darkest recesses of space to visit places that have endured unimaginable periods of time, waiting to reveal their stories of destruction and creation.

• Documentary