For anyone who grew up after about 1940, this is a prophecy fulfilled. We can feel something of the same sense of the essential rightness of the universe as must have filled the Jehovah's Witnesses waiting for the apocalypse in the silly season of August 1914. Our pleasure, like theirs, is rendered all the more delicious by the vagueness of both prophecy and fulfilment. Whatever we expected the Martians to be, it was something more than a trace of chemicals inside in a rock. There is a wonderful inscrutability, a proper alienness, about such a sign from the universe. It may not make us alone, but it gives us no grounds to suppose that whatever may share the universe with us will turn out to be even comprehensible, let alone friendly.
This may seem to be something which increases the amount of mystery in the universe. But in one sense it will be understood by atheists to decrease the mystery of life. If life emerged on Mars, it will have done so by evolution from non-life. Life, to this extent, is robbed of its magic, and its need for a special explanation. It is just something that happens according to the rules of a universe like ours, as gravity is, or electricity; and we don't think of those as mysteries. Perhaps we should: if I am honest, I am still puzzled that Australians don't fall off. I can understand it, and accept as true that they don't, but I can't visualise it. Still, the mystery drains away once the mysterious seems predictable. There is no very good reason for this vanishing act: a universe whose behaviour is predictable according to mathematical formulae is quite as odd as one carried on the back of a giant turtle, and a lot less like anything we can easily imagine.
Is an unmade, unfeeling universe odder or less credible than one which was made to pivot around an act of redemptive agony? There cannot be a good measure of improbability for what is, by definition, the only universe we've got. We can talk about how different the universe of observation turns out to be from the universe of common sense; but it is very difficult to argue that one or the other is more natural or more probable. This is a razor that cuts both ways. Christians who accept the scandal of particularity have no business arguing from the anthropic principle that a universe with life in it is so unlikely as to demand a maker.
On balance, I think, the Martian meteorite will diminish, perhaps unreasonably, the credibility of Christianity. This is not because the central Christian doctrines cannot be easily adopted to make room for it: they can. But there are questions of identity involved. The Christian universe in which other planets are seeded with life - some of it presumably intelligent and in need of redemption - is very different from the universe of most of Christian history. It may not be different in its essentials, but it is different in its emotional colouring.
The strain will come because many - perhaps most - of the Christians in the world are still living in the 19th and preceding centuries. So what would be a nice historical judgement - whether a Christianity fully assimilated to the modern world is really the same religion as was practised by the builders of the great cathedrals - becomes a nasty political dispute. The ancient and modern forms of Christianity have to co-exist; and both tend to be weakened by their struggle. Fundamentalism has not hated the world half as much as it has hated liberal Christianity; and this feeling is more than reciprocated by the liberals.
For at least the last 50 years, fundamentalism has seemed to be gaining strength, and liberal religion dying. It may be that this is purely a matter of sociology. But if there is a doctrinal reason for the popularity of conservative religion then it is surely that it has preserved a sense of mystery and strangeness better than liberal mainstream Christianity has. It's easy and almost always right to mock demands for "excitement" or "relevance" from evangelicals. But their instinct for excitement is surely right. The promise of vibrant religion, just as of real science, is that common sense is wrong about almost everything that matters - and that the earth may turn out to contain frozen threads of evidence for life on Mars.