The landing of the Curiosity rover on Mars can only be described as a magnificent scientific achievement. Even the initial images being sent back are awe-inspiring, and there promises to be a lot more, both of images and scientific data.

I would like, though, to raise a couple of questions about the cost of such projects, both in terms of hard cash and the massive brain power and engineering skills that have been and will be expended. This is not in any mood of grumpiness, and I stand by my opening sentence as to the stature of the achievement. Neither am I singling out NASA here, for similar comments could be made about other projects, notably the LHC, an equally stunning project.

My first question is about motivation. The main purpose of Curiosity appears to be to discover whether there have been in the past conditions on Mars that would have supported life. This allies with all the efforts being made by the SETI institute and other bodies to answer the question of whether there is intelligent life elsewhere in the universe.

My misgiving is that many of those who set our cultural agenda are chiefly interested in this question because they desperately want to believe that there is such life and that we are not alone. Richard Dawkins is the most obvious culprit here – in The God Delusion he acknowledges all the difficulties in such a belief, yet blithely asserts, nevertheless, that the existence of alien life is probable. This is not an uncommon attitude, even among some scientists.

My second question concerns the great amount of humanitarian need in the world that could be eliminated if more scientific and technical skill were dedicated to doing so. Surely if we can send a rover to Mars we should also be able to arrange that food and water (of which there are really adequate supplies) reach human beings that most need them. Not to mention basic sanitation and medical facilities.

If the scientific agenda is being driven in certain respects by a need to find life elsewhere – a kind of secular religion – and if science is capable of solving humanitarian problems here on earth but chooses not to do so, there is only one possible conclusion. We must conclude that for all the wonders of our scientific culture, we have replaced a sense of basic human need with a sense of our own inner need. Or, to put it more dramatically, if that inner need is not met by belief in God, the price of meeting it by other means might be the lives of millions and the well-being of countless others.

It is often argued, of course, that the pursuit of high-status scientific projects has spin-offs that provide indirect benefits to humanity, from medical scanning to non-stick frying pans; but this is a weak argument. Why assume that these discoveries would not have been made with a more direct approach, or as spin-offs from more human-focussed projects?

It may not be, in the end, simply a matter of money. We need, perhaps, to regard scientific and technological expertise as a scarce resource. In that case, how we use such a resource is a major ethical question – the type of question addressed by conventional religion. It would be the ultimate irony if our new secular religion choked off such considerations just when our science and technology are creating opportunities to do so much good.