Next we have sample return. An actual piece of the soil and rock is picked up, stored carefully and then brought back to the Earth-based laboratory. Back here on Earth huge sensitive instruments can be used to probe the material in intricate detail, and we do not have to rely on the remote manipulation of small hardware designed to cope with the rigours of space. Over 350 kg of lunar material have been returned to Earth by the USA and the USSR from nine specific locations. How typical this is of the Moon in general is an open question. The ‘planetary surface’ dilemma still remains. It is one thing to scrape a sample from a planetary surface. We still have little idea as to what the planet is like inside.

The final stage, stage six, is sending someone. Here you have all the advantages of the clever, inquisitive, enquiring human noticing the unusual and taking advantage of the unexpected. But as yet only 12 people have walked on the Moon. This celestial body is only 380,000 km away, and we can get there in three days. And it all happened a long time ago, between July 1969 and December 1972.

Why have we gone into space to observe the planets? It’s more than just our adventurous spirit and unbounded curiosity. Military progress and rivalry between governments played a vital role. Rocketry was designed so we could hurl bombs from one continent to another. The first USSR spacecraft underlined the progress of the communist system and the USA raced to catch up. “Achieving the goal, before this decade (the 1960s) is out, of landing a man on the moon and returning him safely to earth” became the Kennedy rallying call. But there were many before Kennedy pointing to the distant frontier. Percival Lowell’s observation suggested that the surface of Mars was criss-crossed with canals irrigating the equatorial regions with melted polar snow. Life was out there. We had to go and look, and say hello. Space is the final frontier and it would be inhuman not to explore.