Pushing the frontiers of human exploration, on Earth and beyond

Should we be going to the moon, Mars and other places beyond Earth when we are not able to properly explore and take care of our home planet? Is the huge amount of money being spent on extraterrestrial exploration the best investment we can make when we still haven’t seen, let alone mapped, most of our own ocean floor?

These fundamental questions were at the heart of an hour-long discussion, Red Planet vs. Blue Planet, at today’s National Geographic Explorers Festival in Washington, D.C. (#NatGeoFest) The answers may surprise you.

The lively discussion at National Geographic headquarters was moderated by Joel Achenbach, author and staff writer at The Washington Post, and contributor to various National Geographic publications (including Mars: Inside the High-Risk, High-Stakes Race to the Red Planet, National Geographic Magazine, November 2016).

The panel of prominent experts in the topic of exploration of Earth and beyond were:


We have better maps of Mars than of our planet, Ballard, a proponent of focusing more on the exploration of our own planet, said at the start of the discussion. It’s easier to see Mars because 70 percent of Earth is covered by water, he explained. “It’s a much greater challenge to map our planet, although the cost of mapping Mars, I think, was $3 billion…you could map our planet for the same amount of money. We haven’t done it yet.”

What is more, Ballard added, we don’t have maps of half of the United States, because 50 percent of America is underwater [the sea floor within the U.S. coastal territory]. The U.S. has the largest underwater holdings of any nation.

Our blue planet. Credit: NASA

Hadfield, who has been into Space three times, going around Earth 2,600 times, including a space walk during an aurora, advocates for further exploration both on Earth and beyond our planet.

It’s important to encourage exploration, Hadfield noted, because it’s on the frontiers of things that we discover the most. By challenging ourselves to go to an environment we’ve never been before…whether under the ocean or on Mars…the understanding of our own planet and our role on it only comes from exploration and our ability to see it any way that we can challenge ourselves.

“I think we need to continuously push ourselves to do those things. Often the returns are just scientific — you get data…ideas…but what National Geographic has done so well for so long is take those bits of data, those ideas, and turn them into something human, something that inspires us to be even more curious,” Hadfield said.

Chris Hadfield on the first Canadian spacewalk on April 22, 2001. (Credit: NASA)

Bethany Ehlmann actually explores Mars, albeit it remotely, via robots. “My job is not only the Rover driver, but the Rover backseat driver,” Ehlmann quipped. “As one of 400-and-something members of the science team for the Curiosity Rover, we take take turns. There are a few of us who have the privilege each day of getting to be in charge of the decisions of where does the Rover go, where does it drive to, what does it drill, what rock do we shoot with our laser in order to make a measure of its chemistry.”

It’s a whole different style of exploration when you can’t pick up the rock and touch it, Ehlmann noted. “I am a geologist by training. Sometimes this is intensely frustrating…you just want to look at what is on the other side.”

What the Rover does, however, is extend the human presence to another planet, through the eyes of a robot that drives around with a field of view that is about the same height as our eyes. This is incredibly exciting, as each day a data download comes from Mars and you never quite know what you are going to find, Ehlmann said.

Every once in a while, Mars produces a large surprise, Ehlmann added — a “Wow” moment from a planet hundreds of million miles away.

“It goes back to the theme of this discussion ‘Red Planet vs. Blue Planet’, the reason I explore Mars is the question ‘Why did Mars, once a water-rich world — it had lakes…rivers…hydrothermal systems…it may even have had an ocean in the north — why did it go from being a Blue Planet to a Red Planet?’ It’s a hugely profound question, and I want to understand that. This is why I explore with Rovers.”

The red planet. Credit: NASA

Citing Elon Musk’s SpaceX’s mission, which is to enable humans to become a spacefaring civilization and a multi-planet species by building a self-sustaining city on Mars, Stephen Petranek said he believed there could be 50,000 people on Mars by 2050, “a conservative estimate”.

People can’t get their heads around that we’re going to have humans on Mars, Petranek said. “In ten years, I think humans will have landed on Mars, if Musk can build this colonizer rocket that can carry 80-100 people at a time.”

But is this a good idea, something we would want to do?

Exploration is good, but it does boil down to cost, Ballard said. “NASA’s budget is a thousand times larger than NOAA’s exploration budget, so it’s really [about] money. Yes, we should do every kind of exploration we can, but I’m really focused on my own planet. Knowing how little of it has been explored, that 95 percent of the human race lives on less than 5 percent of Planet Earth, I would rather colonize Earth first.”

Chris Hadfield: “Historically, we have explored for three different reasons. One is ideological…a strong core belief, religion or anything else, that leads to exploration…Or it is purely scientific, and that drives some of the current exploration going on. Or the main reason we have ever explored has been financial — it’s why the Portuguese invented all the things they did to get us around Africa, and then with the Spaniards, across the Atlantic, and then across the North Atlantic and the Northwest Passage — and it’s still driving us today. If we look at 10,000 years, or 300,000 years of exploration for our species, of those three historic drivers, and the balance between the three, financial almost always end up being the main discriminator. Where does Mars fit into that?”

While being a big fan of Musk, Hadfield added, “I think it’s his form of ideology that is pushing” the exploration of Mars. “I don’t think that it is going to be financially viable, and what he’s doing is not scientific. The scientific exploration of Mars does not involve settlement and colonization. So I think that as an ideology and a way to motivate people it’s a wonderful idea, and it’s a long-term motivator because we need our young folks to do something that hasn’t been done before. But I don’t think the timeline is realistic.”

What SpaceX is doing is tremendously important, Ehlmann agreed, but it was difficult. Only the United States had so far managed to land robots to explore Mars successfully, and no one had developed spacecraft capable of launching off of the surface of Mars to return to Earth. “All of our Rovers that we send, they’ve gone on a one-way trip. They explore, and then they remain. I think that if we are going to send out a colony, we might want some two-way traffic and at least some supplies and materiel, especially if there is a financial side to this.”

But what Musk and SpaceX are doing is tremendously important, Ehlmann added, because the reusable rockets are being the catalyst to create access to Space at a cheaper cost. “A number of companies are pursuing this. And that’s the most important catalyst, getting that cost of access to orbit down.”

Ehlmann supports sending human explorers to Mars. One big issue still to resolve, she said, is whether there was life on (or if there is life in) Mars. Exploring remotely via robots requires a time lag of as much 25 minutes between sending an instruction to a robot and it being received on Mars, which is a barrier to experiencing the environment in the same way that a person would on the Red Planet, she said.

“NASA is sending a Rover in 2020 specifically trying to begin the process of landing at a site that we think could have had life in the past, to answer the was question,” she said. There are signs of what could have been the presence of water, and parts of the planet do reach temperatures above the freezing point of water, she added. So this meant we need to be careful. “We need to send robots to some of these most interesting places to see if Mars is a world with a second genesis. That will tell us something really profound about how rare or how common life is in the universe…That requires great care to avoid messing up the one-shot experiment of seeing whether there has been a second initiation of life.”

NASA image of the Mars 2020 Rover

The whole question of whether you really want to colonize Mars is kind of separate from this discussion, Stephen Petranek said. “Exploration has probably been built into our DNA for 95 percent of the time that humans have been Homo sapiens. We have moved on beyond our present horizon into a new wilderness, because we’ve learned as a matter of survival that that is a way to stay alive.

“That’s actually true for humans on Earth. Within a million years, as our sun begins to age, it’s either eventually going to throw Earth completely out of its orbit or it’s going to radiate all life on Earth to death. So if you want the human species to not go extinct, you must become a Space-faring society. And the sooner you start that, because it’s a long learning curve, the better. Mars is really, honestly, just practice to get us completely out of the solar system, eventually. Because even Mars will face the same threats that Earth faces. Mars is not a permanent solution to keeping humans alive forever.”

Humans are not going to abandon Earth to go to Mars, Petranek added. “The point is to develop the expertise to be able to move on inter-planetarily and eventually [from] the solar system. That makes a lot of sense for humans.

“You know, we all think that technology is magical and it just moves ahead all by itself, and it just keeps getting better and better, but pull out your iPhone 7 and look at an iPhone 4; it’s basically the same machine. The only thing that moves technology is a push, and if we send humans to Mars, the technological push that is necessary is going to do the same kind of things that happened in the Sixties with the Apollo program.

“I don’t think most people realize just how much of the technology that’s around all the time now either came out of World War II, when there was a huge push in technology, or in the Apollo program.

“Learning to go to Mars and keeping humans alive on Mars will actually allow us to get much better in controlling our own planet and understanding our own planet. And it will give us technological tools we don’t have now that will be really important in the future.”


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  1. Ron
    June 25, 4:20 am

    I find it bizarre and completely backwards that people are seriously proposing trading a vibrant and still lovely world for a utterly dead and hostile rock in space, ironically giving as reason that something might happen to threaten life on the living world. That’s like saying, well even though I do have this delicious and nutritious meal before me, something might come along to ruin it. So I think I’ll just have this moldy, maggot invested carrion instead. Maybe I can clean it up, add a few spices to it.

    Certainly, there are a lot of big problems with the Earth thanks to us, so having another world would be nice. But it’s pretty crazy to pretend that Mars would somehow be preferable to earth, in ANY state of ruin. Lots more here: