Curiosity has lots of potential for doing more things than all the previous landers put together and doing those things in a coherent way. Not only does it have a large package of experiments it can do, but it can move about ten times faster than Opportunity. And it can travel within the ideal location without having to depend on sunshine to power its actions or batteries to keep it warm at night and risk failure in winter. All of its components have been tested for four years of minimum life and most can probably last much longer.
If ever there was life on Mars there is a good chance that Curiosity will find it. Even if Mars was never in the known Goldilocks zone of a habitable planets it may still have developed life. But that is unlikely. However, when we consider that our Sun is a common star in a common galaxy it really doesn’t matter much if Mars did have life; it just makes it all the more common. Either life can exist or it can’t, and since life exists here on Earth, it makes it nearly as inevitable as gravity that life exists on at least some of the almost infinite number of planets in the Goldilocks zone. We will never know of those life forms because they are so very far away, unless, as Craig Venter has proposed, life is expanding in the Universe at the speed of light. He proposes radio broadcasting DNA sequences and the way to form them into living beings out to distant stars and galaxies. Perhaps other beings are already broadcasting DNA sequences to us at this time and we just haven’t picked up the signals, or have picked them up but didn’t recognize them.
Mars may or may not have life, but a few years from now, if it ever had very much life we will probably know, and that will be a fantastic announcement. If life never existed there, that will be announced too, but then we will probably keep searching for it, but never know for certain that it didn’t exist somewhere there on Mars where we didn’t or couldn’t look. Curiosity is in good health and will be looking at various places that were at different times the bottom of an ancient dried up big lake. If ever there was life on Mars some of it would have been there and if it was there it will have left some traces.
There have been some Martian meteorites found in Antarctica that had some very strange potential fossils of living things, but they were too few to make definitive claims. However, if Curiosity finds these same “fossil things” in rocks and other similar things in deeper layers showing evolution that will probably prove convincing.
If our society holds together for a few more years, we may know we are not alone.