Oh Tang! If our seas rise too high there are exoplanets to settle. But hope you like freeze-dried food, because it’s a long trip out there.
This illustration shows a fictional astronaut on Mars, as viewed through the window of a spacecraft. (NASA/JPL-Caltech)
Every inhabitant of our planet is affected by the far-ranging consequences of climate change. The quality of our future on Earth will be determined by how we meet the challenges of global warming.
But there are people who speculate that the answer to a catastrophic failure of Earth’s eco-systems is to migrate to “Planet B.” That planet is Mars, according to SpaceX founder Elon Musk.
His plan, titled “Making Humanity a Multi-Planetary Species,” includes a discussion of a Mars colony and has attracted a number of supporters. Musk isn’t the only person who has looked to an off-Earth future for humans.
Can our species re-locate to a life on Mars?
Mars is very cold. At minus 55C, it’s the temperature of Antarctica in winter. Musk has suggested that exploding a series of nuclear bombs over the poles of Mars would melt the ice and help “terra-form,” or modify, the environment to make it habitable. Others have calculated it would take thousands of nuclear explosions to achieve this goal.
“Nuking Mars raises a host of scientific, ethical and legal questions,” said Jatan Mehta of The Planetary Society, a nonprofit organization co-founded by Carl Sagan.
Space to breathe but, alas, no air
At least in Antarctica there is air to breath even if it is cold. The lack of a protective magnetic field on Mars means there is an atmosphere less than 1% that of Earth. In other words, don’t take off your space helmet on the red planet.
“Although the current Martian atmosphere itself consists mostly of carbon dioxide, it is far too thin and cold to support liquid water, an essential ingredient for life,” reported Bill Steigerwald and Nancy Jones of the U.S. National Aeronautics and Space Administration (NASA). “Any liquid water on the surface would very quickly evaporate or freeze.”
So no air and no water on Mars.
There are other challenges to human health even to reach Mars, according to the European Space Agency (ESA). On a trip that would last eight months, astronauts would face radiation doses up to 700 times higher than Earth. That, says ESA, is a “major showstopper for safe exploration.”
So, what should we look for in a potentially liveable Planet B? An atmosphere of breathable air and one that protects us from harmful radiation is a good start. A “Goldilocks” temperature — meaning not too hot and not too cold — would ensure human-friendly temperatures and the existence of liquid water.
Exoplanets are light years away.
Looking beyond our solar system, with no human-friendly options, we can examine more than 5,000 exoplanets we have discovered. With the James Webb Space Telescope making remarkable discoveries in different light spectrums, we know much more about them now. The telescope has revealed atmosphere on planets with distinct signatures of water.
One intriguing planet, which has been dubbed “comfortably habitable” according to NASA computer modelling, is the closest potentially liveable “Planet B.” But there is a problem. Planet Kepler22b is 635 light years away.
The distances in our universe are astonishing. Even in our relatively small solar system, a tiny part of the Milky Way galaxy, spacecraft take nearly 10 years to reach Pluto from Earth. And Pluto is only 4.6 light hours — hours not years — away from Earth.
A journey to Kepler22b requires 635 years of travelling at the speed of light — a mind-boggling 186,282 miles, or 299,792 kilometres, per second.
At the speeds of our space craft, it would take 37,200 human years to travel one light year. Which means 23,622,000 years of freeze-dried food to get to Kepler 22b.
Let’s use space technology to stop climate change.
Science fiction lovers who follow the Star Wars films may think fondly of the Millennium Falcon starship, which was piloted by Hans Solo and could travel in “hyperspace” to exceed the speed of light. Sadly, this is possible only in Star War films.
But actual science — as opposed to science fiction — is even more remarkable and has made us a space-travelling species.
The Apollo Moon missions allowed us to look at Earth for the first time from another celestial body. Before the Apollo 8 mission orbited the Moon, no human was able to see the whole Earth in one view. The famous “Blue Marble” photograph evoked a sense of wonder as our planet, teeming with life, seemed to hang in the darkness of space.
Michael Collins, the astronaut who piloted the Apollo 11 mission that delivered Neil Armstrong and Buzz Aldrin to the lunar surface, wrote in 2008 about his view from the command capsule. “When I looked back at Earth from the Moon, if I could use only one word to describe the tiny thing, it would have been fragile. A totally unexpected reaction, but fragile turns out, unfortunately, to be accurate in a thousand ways.”
Apollo, which carried the orange-flavoured drink Tang on board, taught us about the Moon, but we discovered even more about the Earth. And the remarkable technology which delivered men to the Moon has grown and evolved.
The sophisticated Earth observation satellites increase understanding of our planet and allow us to monitor and measure every aspect of our atmosphere, land and oceans to understand and mitigate climate change. Perhaps using our astonishing space technology to heal our planet might be more helpful than hoping to re-locate to Planet B.
Questions to consider:
- Why do some people think that space travel is an answer to our climate problems on Earth?
- Why would it be difficult for humans to live on Mars?
- If it were feasible to send humans to far-off planets, would you want to go there? What would you be willing to leave behind?
Tira Shubart is a freelance journalist and media trainer based in London. She has produced television news and trained journalists across four continents for international broadcasters, including BBC News, Canadian Broadcasting Corporation and Al Jazeera, over several decades. She is chair of The Rory Peck Trust and a Fellow of the Royal Astronomical Society as well as Ambassador for the Science Museum in London.