SpaceX CEO Elon Musk wants to have a city of a million people on Mars by 2050. That may sound astronomically ambitious considering humans have never set foot on the Martian surface. But is it feasible? How long would it take for humans to colonize another planet? And could it ever be possible for people to colonize worlds outside the solar system?
The answers to these questions depend heavily on which planet you're talking about. For Mars, decades isn't necessarily an unrealistic time frame. Serkan Saydam, deputy director of the Australian Centre for Space Engineering Research and a professor at the University of New South Wales in Sydney, said human colonization of Mars is possible within decades.
"I believe by 2050 we will have a human colony on Mars," Saydam told Live Science.
Saydam is a mining engineer who specializes in researching future mining. The first major step in establishing a successful Mars colony will be water, and that can be extracted from ice and/or hydrated minerals, according to Saydam. He thinks water will then facilitate agriculture and the ability to grow food on Mars, like in the 2015 movie "The Martian," while hydrogen from the ice and minerals could also be used as an energy source for rocket propellant.
But there isn't a scientific consensus on Mars colonization by 2050, and other scientists have offered less optimistic opinions. Louis Friedman, an astronautics engineer and co-founder of the nonprofit The Planetary Society, suggested to Gizmodo in 2019 that Mars colonization was unlikely for the foreseeable future, while Rachael Seidler, a neuroscientist at the University of Florida who has worked with NASA astronauts, told Gizmodo that people like to be optimistic about colonizing Mars, but it sounded "a bit pie-in-the-sky."
Humanity will, however, likely reach Mars within decades. China plans to start sending human crews to Mars in 2033, while NASA aims to send astronauts there by the late 2030s or early 2040s. Once humans get there, the next step could be to build a colony.
Colonization implies some degree of self-sufficiency but not necessarily complete independence from Earth. Saydam compares Mars with a remote island where you'd still need to import things occasionally. "Most of the equipment and tools will be sent from Earth," Saydam said. "I don't think you can manufacture a truck on the Mars surface."
Mars would need to produce something for a long-term colony to be financially viable. Space tourism is one option, but Saydam pointed to mineral extraction as key to colonization success. For example, space mining on nearby asteroids for valuable materials such as platinum could create new space economies, thereby driving further investment and exploration.
Though Mars is our most realistic option for extraterrestrial colonization, our red neighbor isn't exactly the most accommodating planet for humans. Mars' atmosphere is more than 95% carbon dioxide; it's really cold, with an average temperature of around minus 80 degrees Fahrenheit (minus 60 degrees Celsius); it takes spacecraft from Earth about 8.5 months to reach; and it's bombarded with harmful radiation.
There's almost certainly more hospitable new homes to be found on planets beyond our solar system, called exoplanets. The problem with exoplanets is that they're very, very far away. We haven't even sent a spacecraft to an exoplanet, and the only probes to leave our solar system were Voyager 1 and 2, which took 35 years and 41 years, respectively, to go interstellar. Exoplanets are much farther away.
"The closest exoplanet would take several tens of thousands of years to reach with our current technology," Frédéric Marin, a black hole astrophysicist at the Astronomical Observatory of Strasbourg at the University of Strasbourg in France, told Live Science.
Those travel times may make exoplanet colonization sound impossible. But Marin, who runs computer simulations for interstellar travel as a scientific curiosity, expects them to plummet in the near future, thanks to faster spacecraft.
"We know in science that every hundred years, every century, the velocity of your means of propulsion increases by a factor of 10," Marin said. In other words, as humans learn how to travel faster and faster in space with each passing century, the potential travel time to exoplanets could drop from tens of thousands of years to thousands of years, and then to hundreds of years.
Marin laid out a hypothetical scenario of reaching an exoplanet that's at least hospitable to humans within 500 years. A journey lasting centuries would still require a spaceship piloted by multiple generations of humans, most of whom would never see the exoplanet that's eventually colonized.
Marin's simulations suggest that around 500 people is a suitable starting population for a multigenerational colony ship. But how humans would cope with spending the rest of their lives on a spaceship and how their offspring would handle being born into interstellar travel life raise ethical questions and uncertainties. And with climate change and other Earth-based challenges threatening to drive humans to extinction before we crack interstellar travel, there's no guarantee we'll ever colonize exoplanets.
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Patrick Pester is a freelance writer and previously a staff writer at Live Science. His background is in wildlife conservation and he has worked with endangered species around the world. Patrick holds a master's degree in international journalism from Cardiff University in the U.K.
Let's see someone make a living on top of Mt. Everest first. That is a much easier environment.Reply
Quantum entanglement was recorded to 'travel' at 10.000 times the speed of light. Perhaps if 10^20 of such strings can be attached between two plates with a 2-meter diameter and placed between Mars and Earth we could create a subatomic tube with no gravitational force inside wherein a small manned craft can travel from Earth to Mars and back in just a fraction of a second. It would take a million x a billion times the speed of light though to reach the thus far known end of our universeReply
I wish it wasn't so, but there isn't a planet in our Solar System where Homo Sapiens can survive for any length of time.Reply
Elno can try to have fun on Mars, but colonization will never be successful. The travel time to an Earthlike planet in another solar system makes that journey impossible.
At the rate we are going, human survival on Earth will be very brief, on a geologic time scale. Just look at the destruction we've caused in a few hundred years :disrelieved:
The Sherpas make a very nice living indeed guiding fools up and down Mt. Everest!Reply
Nope................Theo Prins said:Quantum entanglement was recorded to 'travel' at 10.000 times the speed of light. Perhaps if 10^20 of such strings can be attached between two plates with a 2-meter diameter and placed between Mars and Earth we could create a subatomic tube with no gravitational force inside wherein a small manned craft can travel from Earth to Mars and back in just a fraction of a second. It would take a million x a billion times the speed of light though to reach the thus far known end of our universe