Last weekend, I had the opportunity to talk about Mars One with a crowd of art-lovers who also appreciate astronomy (or, perhaps, astronomy devotees who also appreciate art). The format was a panel discussion on Mars exploration with a focus on astrobiology (i.e., the possibility of life on the Red Planet), and the venue was Grumpy Bert, a gallery and event space in Brooklyn run by  (Here’s a flyer for the event.)

I shared the stage (the staircase, to be precise) with Caleb Scharf, Director of Astrobiology at Columbia University, and our conversation was mediated by Miriam Kramer of SPACE.com. The event was facilitated by Summer Ash, Director of Outreach at Columbia’s Department of Astronomy.

Summer live-tweeted the event, and I’ve compiled her photos and tweets (along with some images taken by gallery owner Albert Chau, the eponymous Grumpy Bert) as a Storify, here.

For the first part of the discussion, Miriam guided Caleb and me through an overview of our reasons for believing that Mars was once a warm wet world, potentially hospitable to life as we know it, and how past life might have left traces in the soil and rock of the planet.

Throughout the conversation, we repeatedly returned to the mantra of astrobiology: “Follow the water.” Thanks to the efforts of several robotic missions, we are now fairly confident that the Martian soil contains a significant percentage of water (as ice), and that water may still flow on or immediately under the surface under some conditions during warmer seasons. This led to some enjoyable speculation about how life might still persist on Mars, possibly deep beneath the visible surface, analogous to the subsurface lithoautotrophic microbial ecosystems (SLiMEs, one of the best acronyms ever) here on Earth.

Caleb was a delightful partner for the event, and (unsurprisingly, given that he actually does astrobiology for a living), I learned a great deal, especially about the ancient history and evolution of Mars (about which more below). We also had really good stage chemistry, and our interactions led to some memorable exchanges:

We could probably have continued in that vein for hours, but we also wanted to open the floor for questions, which occupied the last half of our time on the stairs. The audience was enthusiastic about every aspect of the topic, and the questions were split roughly equally between Martian planetology and more directed queries about Mars One. Here are a couple of quick examples, based on some notes I took (on my hand) while we answered:

Q: Why is Mars dry? (i.e., where did the water go?)

A: We’re not sure, and because we don’t actually know how much water was originally present, it’s hard to make confident assertions about where it went. (It’s worth mentioning that there’s still a huge amount of water on Mars in absolute terms, enough in the southern polar cap to cover the planet in an ocean 10 meters deep, so one might just as well as ‘Why is Mars cold?’ Turns out the answer is related.) Caleb offered a number of possible explanations, most of which ultimately invoked Mars’ (present) lack of a magnetic field: no planetary dynamo –> no magnetic field –> no way to hold on to hydrogen ions produced when atmospheric water is split by solar radiation.

Q: Is radiation exposure an obstacle to permanent settlement on Mars? 

A: My thinking on this is evolving, but the basic framework for my answer is that radiation dose is a function of the environment and the technology we bring with us. One of the major controversies about Mars One is whether the project’s plans for radiation abatement are sufficient, and at the moment that’s still an active debate. That said, there is certainly no inherent reason why radiation would be an absolute barrier to success; we just have to make sure that we use the right shielding technology for the interplanetary voyage, and then get under as much rock as we can as soon as possible once we’re there. Which leads us to…

Q: Why don’t you plan to live in caves?

A: In some ways caves would be optimal, and from orbital imagery we already know that there are many, many caves on Mars that are open to the surface. Indeed, serious thought has gone into choosing the right caves for human settlement (q.v. the Caves of Mars Project). That said, the Mars One landing site (TBD) will be chosen subject to a large number of constraints: far enough north that there’s plenty of water in the regolith; far enough south that solar power could be collected efficiently; and flat enough that the landing itself is straightforward. If there’s a cave near an appropriate site, then I say go for it. That said, there might not be.

Q: Will you terraform Mars?

A: Not me personally; it takes kind of a long time. Early efforts will focus on constructing enclosed habitats in which humans can live increasingly independently of pressure suits and radiation shielding, but without any efforts made toward true planetary engineering. The audience member followed up by asking the possibility of domes, to which Caleb replied by describing something I’d never thought of before: rather than freestanding domes, settlers could tent existing valleys, taking advantage of the natural protection of the rock and requiring less shielding material to boot—”like a human-made cave with a skylight.”

There were many more excellent questions—about the psychological stresses of a one-way trip, the structure and architecture of the settler’s habitats, the rate of meteorite strikes (which I really need to look up), and a variety of planetological issues. Overall, we had a fantastic and wide-ranging discussion.

Afterward, the venue opened into a gallery showing of Mars-themed art, which you can check out here. (Some of it is still available.) I was tempted to purchase some myself, especially the APAK piece that was used for the event flyer, but sadly it was a bit too rich for my blood. Rich benefactors, contact me via the form on the About page 😉

As we wandered through the intimate gallery, the conversation broke up into one-on-one interactions devoted to follow-up questions. I met a number of fantastic people, many of whom I’ve stayed in touch with on Twitter. The overall tone was one of excitement, curiosity, and wonder. From what I could see, many people who walked in with no idea that the Mars One Project even existed walked away convinced that it could succeed. More importantly, everyone (including me) learned a great deal about the science of Mars (and science on Mars), and I consider the event to have been a smashing success.

Many thanks to Caleb, Miriam, Summer, Albert, and Lynne for a fantastic event. I’m actively seeking more opportunities to talk about the project (and Mars in general) to groups of whatever size in the weeks and months to come.