Life on Mars with Pete Worden
Pete Worden is the Director of the NASA Ames Research Center and an Advisor to the Space and Physical Sciences Track of Singularity University. We caught up with Pete on the NASA Ames campus, where we talked about what we’ve just learned about Mars and how self-replicating robots will be used to colonize space, among other things.
h+: What have we learned recently about Mars and the possibility of life there?
PETE WORDEN: Well, from what we’ve seen and the missions we’ve had, Mars is obviously an environment that can support large-scale human activity. It has substantial quantities of water and other “volatiles” — carbon compounds and so forth — so it clearly can support life. In fact, it may already be supporting life, and that’s one of the main things we need to find out before we do anything, because there may be microbial life below the surface of the planet.
We announced recently — and this is actually from Earth-based observations — that there is evidence of variable methane on the planet. This could mean that there is some sort of geologic activity going on underground, with its own source of heat that would melt water and allow flows underground. This would be exciting in its own right, for we have long thought that Mars was a geologically inactive, “cold” planet, like the Moon. However, since life can also cause methane to be produced, our first objective is to find out if there is already life there.
h+: And that’s where the robot missions come in?
PW: Yes. The possibility that life exists currently on Mars suggests that we’re going to have to do extensive robotic exploration here on Earth. Mars is obviously an environment that can support large-scale human activity. I don’t want to take the chance that we’re on the losing side, until we find out what it is, and if it’s compatible with Earth life, or not. There’s also a possibility that Earth life is Mars life. The first life forms here may have come from Mars. We don’t know. It may be more compatible than one would think. But, at any rate, it’s a very interesting scientific question.
h+: But you’re also trying to be careful not to introduce any harmful bacteria to anything that might already be living on Mars?
PW: Exactly. Until we understand the full biospheres of both planets, we’ll want to be careful. So, sterile robots can begin to help us do that. We’re pretty sure that there’s no life on the surface of Mars, or at least nowhere we’ve looked, but there may be life sub-surface. We already know from the Phoenix Lander that right below the surface is a permafrost. One of the things we’re doing here at NASA Ames is developing autonomous robots and drills that can drill down into that permafrost. We learned from Apollo that it’s hard to drill on other planets. The rock characteristics are different… and different in a way you can’t predict.
We have already done a lot of work on autonomous robots, which is the first step. Many of the Mars robots we’ve sent there have JPL on the outside and NASA Ames on the inside, since a lot of the software has been developed right here.
Next, we’ll want to build self-replicating robots, and that’s why nanotechnology, artificial intelligence, and other technologies being worked on at Singularity University are so interesting. When you start looking at self-replicating robots, a biologist would tell you “Well, we already know how to do that. Those are called living cells. Microbes,” in particular. So one of the obvious questions is: Can we begin to take existing microbes and engineer them to do things? And then, at some point, can you actually create synthetic life that can be engineered to extract the materials you need and construct environments?
We have a research group here at NASA Ames that is looking at “extremophiles,” life forms able to operate under highly extreme conditions, such as close to the boiling point of water, or in highly acidic conditions. These conditions may or may not represent exactly what you’d find on Mars, but we’ve been able to extract these self-replicating proteins and are beginning to figure out how you can replicate them to manipulate metals to construct substrates, and maybe even grow an electronic component.
h+: Are you talking about creating “synthetic life” that will duplicate what’s going on with biology?
PW: Yes. Eventually. But at first, we’re just using what we’ve already found in nature. In fact, there was an article the other day about using viruses to create batteries, and that you can modify the genome of a virus to construct battery leads (+, -), to create a kind of “nanobattery” using the viruses.
So rather than using the current manufacturing process, where somebody melts metal and pours it into molds and machines those parts together into an electrical component, in the future, we’ll use microbes and proteins to “grow” them. In a cell, a particular genetic coding manufactures a particular kind of protein that it links to build, say, a cell wall. Well, supposing we modify that so rather than building a cell wall, it builds a substrate for an electronic component. It might be a simple modification to say, “OK, build this in a flat area.” Then you have another one that comes in and says “OK, every few microns we have an electronic lead.”
Mars may already be supporting life.
The next step — and this is one that is speculative — is creating synthetic life. People like Craig Venter are beginning to do this. If we can actually understand the programming languages of DNA and RNA, which are basically natural computers that are able to replicate themselves, we can, potentially, write code to do things…. It would be like software. So, if nature hasn’t already developed something that can build a brick, we can instead program artificial life to build a brick. Now, that may be decades away, but, maybe not. I mean, there are a lot of people working on this.
The next order of business, if we truly are going to “settle” another world, is that we have to create some sort of environment that’s more hospitable than Mars’ current surface conditions. Mars has less that one percent of the Earth’s atmospheric pressure (that’s like being above 100,000 feet), and the temperatures and other extremes are pretty substantial. People obviously can’t live there.
h+: Enter “cyanobacteria”?
PW: Yes. Cyanobacteria is one of the earliest and most common life forms on Earth. Maybe the earliest, having existed for over 3 billion years. It’s what converted the Earth’s early atmosphere, which was a reducing carbon dioxide atmosphere, to its current oxygen atmosphere. Cyanobacteria are able to convert sunlight, in the presence of water and a few other materials and carbon, into life, and it also produces other carbon materials that can actually be used for fuel. In fact, they’ve already programmed cyanobacteria to produce ethanol from photosynthetic life.
The life that exists today on Earth, including us, is supported by these processes. So, one of the objectives is to determine if we can use what we find there, or modify it, or create synthetic forms of life that will enable us to operate on Mars, and convert its environment, at least on a small scale.
In the near-term, on the Moon, which we’re going to go to before we go to Mars, we can begin to understand more natural alternatives to using chemical reactors to clear the air, such as running air through canisters of cyanobacteria that consume the carbon dioxide and release oxygen. So, it’s a scrubber. In the longer term, we’ll want to see if we can modify it to operate in different temperature ranges and radiation conditions.
If we really want to settle Mars, and we don’t want to have to carry millions of tons of equipment with us to duplicate the way we live on Earth, these technologies will be key. Ideally, at some point, hundreds of years in the future or maybe sooner, people can go to Mars, and take some seeds with them to plant in the Martian soil that will produce a house and an environment they can live in. It’s obviously going to be more complicated than that, but that’s the vision.
Lisa Rein is the Digital Librarian for the Timothy Leary Archives, a co-founder of Creative Commons, and a consultant for Ray Kurzweil’s Kurzweilai.net.