As NASA, along with the European Space Agency, plan a return mission to either Jupiter or Saturn, two prominent astronomers discuss which planet we should return to.

The gas giants Jupiter and Saturn are magnificent and mysterious worlds, surrounded by moons which still perplex the astronomers with their strange appearance and incredible diversity. Europa, Jupiter's moon, offers the best chance yet of finding life elsewhere in our solar system, while Saturn's moon Titan, with its complex organic chemical lakes and a shore line uncannily like Cornwall, is now believed to be like the primeval Earth.

The Large Binocular Telescope in Arizona promises a revolutionary way to look at the night sky. The light from its two eight-and-a-half metre mirrors will produce images of unprecedented clarity and power, offering a glimpse beyond our solar system to the very beginning of time.

Dr Chris Lintott visits Arizona to see the telescope first hand, while Sir Patrick Moore talks to the astronomers who will use it.