At the end of August, I got a press release saying that a chemist named Steven Benner was going to deliver a lecture in Italy in which he broached the idea that we might descend from Martians.

I met Benner ten years ago. He was sitting in a coffee shop in Cambridge, Massachusetts, working out what it would take to make life from scratch. Helping him in this exercise was Jack Szostak, a Nobel-prize winning Harvard biochemist whom he had known for years. In the midst of their conversation, Dr. Benner abruptly turned to me and asked, “How much do you think it would cost to create a self-replicating organism capable of Darwinian evolution?”

As a journalist, I’m not accustomed to such questions.”Twenty million dollars?” I blurted.

“Ridiculous,” I thought to myself. But Benner just tilted his head, looked away, and nodded in thought.

“That’s what Jack says,”he said.

Benner, a distinguished fellow at the Westheimer Institute at the Foundation for Applied Molecular Evolution in Florida, has balanced his career between two ways of doing science. On the one hand, he is a data-driven chemist who publishes papers with heart-stopping titles like, Labeled nucleoside triphosphates with reversibly terminating aminoalkoxyl groups. On the other hand, he is the sort of scientist who enjoys trying to draw up Frankenstein’s budget, or investigating whether life could exist in the liquid methane oceans of Saturn’s moon Titan.

So I knew that he’d have something interesting to say in his talk about Mars.

Not surprisingly, many reports have gone for the Little-Green-Men angle. But when I caught up with Benner, we ended up talking not about alien life, but about the philosophy of science–about how to investigate the origin of life when it happened so long ago and we still have so much left to learn about it. That conversation is the subject of my new “”Matter”” column for the New York Times. Check it out.”