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Science & Tech

Mars: Exploring Mars, Geology, and Astrobiology

Chris Hadfield

Lesson time 15:04 min

Chris discusses how finding life on Mars could deepen our understanding of the universe and illuminate our place within it. Learn how we’re working with robots to search for life and build an outpost on Mars.

Chris Hadfield
Teaches Space Exploration
The former commander of the International Space Station teaches you the science of space exploration and what the future holds.


CHRIS HADFIELD: What would happen if you discovered life on Mars? It's interesting to think about. What would you do if you saw this fossil and it's got, I don't know, nine legs or no legs at all, or it looks like, you know, some weird shape? It looks like a boiled egg or a fried egg or something, but you can recognize that this is a fossil in a Martian shale. What would your reaction be? But maybe, more importantly, what would the world do? What would people think-- to know that we are not alone in the universe? That life is not unique to planet Earth. It would affect a lot of people's fundamental beliefs-- their assumptions as to the preciousness and the uniqueness of life itself. A lot of their sort of unspoken belief system, maybe all wrapped up in the fact that Earth is somehow an expression of what life is, and everything else is nothing. To know that there's life on Mars, it's a very small step to then realize that all of those little points of light in the sky are just as probably places where life either has existed or does exist. And you just have to look around and realize there's not just bugs here on earth, but there is intelligent life. There's sentient beings has developed on this planet, and if there can be life on Mars, no matter how primitive, then there can be intelligent life out in the universe. And there are essentially-- our best satellites and telescopes have told us, there are essentially an unlimited number of stars and planets out there, but right now we're just guessing. But if we can actually find true evidence of life, even as close as Mars, then we could look up at the night sky with confidence that there is life all through that sky, and it's been going on for billions of years. And then the question is, what do we do with that information? How does it affect me personally? How does it affect what we should be doing scientifically? How does it affect the future of our own planet? How should we be taking care of this planet the same way? Does it reinforce our necessity? Maybe that other life is a threat to us. Maybe they have made inventions that we haven't got to yet. Maybe there's a way that we can figure out how to cross the vast gulf of distances between here and there and learn directly from them. Should we be concentrating more on trying to communicate across the vastness of space? Listening more carefully to the quiet signals that are coming from the universe. It will be a great moment of introspection for humanity, I think, if you're the person that finds that one little fossilized flower on Mars. If you get hired as an astronaut, you're probably going to work in the astronaut office for 10 years minimum, maybe 15. In my case, I was an astronaut for 21 years. It's really difficult to predict what is the space program going to be doing 15 years from now. The knowledge that we teach you today, is that going to be the knowledge that you're going to need a dozen years from now? Ma...

About the Instructor

Impossible things happen. At age nine, Chris Hadfield knew he wanted to go to space. He eventually went there three times, becoming a commander of the International Space Station. In his MasterClass, Chris teaches you what it takes to explore space and what the future holds for humans in the final frontier. Learn about the science of space travel, life as an astronaut, and how flying in space will forever change the way you think about living on Earth.


Students give MasterClass an average rating of 4.7 out of 5 stars.

I'm not trying to be an astronaut, but I'm fascinated by space and technology and Chris Hadfield is one of my heroes. I am currently studying software engineering and there was so much perspective and motivational material in here that you can apply to any discipline. I absolutely loved this course and I'm pretty sure I'll watch the entire thing again before too long.

I took this course as a "fun" way to take a break from the film and music courses for which I signed up for. But I quickly became more interested in the subject and stuck with it till the end. I am not going to pursue space exploration, but I got inspired to reach for the stars in my own way.

The class was really interesting and insightful. He covers a vast array of topics, from orbital mechanics to how difficult it is to move in a space suit, in a way that makes it easy for a liberal arts major to follow and understand!

The way that Chris tell and share his knowledge about space exploration is just marvelous. Huge congrats



Nine legs? Nine is a pretty horrible number for legs. I hope not. I think all odd integers are probably bad design. I think that nearly all Geologists or Earth Scientists would consider it a dream to study the Moon or Mars. Each grain of sand would be interesting. So much new information. Every day would be full of new mysteries and discoveries.

Maddie W.

I really enjoyed listening to Chris talk about the societal implications of finding life on Mars as well as the scientific impact. He so beautifully articulates the need for humans to explore this new frontier, to touch and see and really understand Mars in a way that everyone on Earth will be able to appreciate. It truly will be "a great moment of introspection for humanity." In thinking of the international cooperation required to build the ISS and what will be needed to send humans to Mars, it gives me great hope to remember that despite all the conflict we may experience on Earth, humanity will always unite in our common goal of exploring the universe.

Steve H.

It amazes me to think about creating a space station orbiting Mars that could control robots working on the surface of Mars. Considering the time, treasure and resources necessary for the ISS, this would be a huge undertaking because of the distance/time from Earth.


Chris' description of the breadth of knowledge required speaks to the renaissance-ness of space explorers. Truly fascinating...Ambassadors of knowledge.

Sergio N A.

Maybe one of the source of energy in Mars may not be solely on Solar cells because Mars is a very dusty planet with large dust storms. I would choose a Fusion reactor as a major source of energy and that solar can be just a secondary source.

Denny C.

The Drake equation by Dr. Frank Drake details the possible number of livable planets with sentient life on them. While all theory, it shows that if there is not, its a great wast of space.

Denny C.

I believe we will not have too much a problem with life being found on other worlds if its simple life like molds, algae or related types. But if we find life that is intelligent/sentient then our society will have a major problem accepting it. Just as we still have those that want to believe the world is flat or that we faked the moon landings, we will have real-problems with religious -centered belief systems. Riot, suicides and the like will occur. I have no solutions to offer in this realm except desensitization and in a way, science fiction books and movies have done a little for this but not currently in a way to offer help for those who refuse to (don't tell Mulder) believe.

Pedro C.

It was great to listen to Chris talking about the significance of the learning challenges, especially about "being there and experiencing it". So inspiring. It was great also to reflect on the implications about finding any sign of life in Mars, even finding fossiles, life from millions of years ago, it would meen that there was/is life some where else, so, there should be life every where in the universe!!! Connecting to efforts from SETI, and concrete experiments to be done on the pursue of life "out there" would have been even greater.


I love how there's so much similarity to the ocean. To listen to Chris talk about Mars the way he does just adds another layer of reality to the possibility of life outside of the Earth.

Kah C.

I’ll bet many people centuries before who question the explorers. Those who can’t see the point of stepping out of their comfort zone. Why bother to get on a square rig sailing ship for a year or more, sail off to the edge of the earth and fall off. Why? To see what the end of the world is like? You’ll just fall off. There is probably nothing out there nevermind finding gold or spices or meeting other sorts of people. We have civilisation and it works fine. We have a nice business fixing shoes. What is the point in going to Somé place with nothing there. No buildings or rum. It’s just like those who think electric cars won’t work. It’s like the car when it was first introduced. My horse and carriage will do just fine for me. I don’t need a new fandangled contraption. I can feed my horse everywhere I go. Where can I get this gasoline stuff. No the car won’t work. The horse and carriage will be with us forever.