In the last 100 years, the thoughts of moving to another planet have not only been in the realm of science fiction but also out of general concern of the future well being of civilization.
With the draining of Earth’s resources and the slow advancement of our planet’s doom, we are obliged to ensure progress and stability for the future generations. And, if making another planet our home is an option, we might as well try it.
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What planets can we travel to?
As of now, the fastest moving man-made object is Voyager I. It travels at 17.043 km/s (10.590 mi/s) relative to the Sun. At this speed, it will take around 17,565 years to travel 1 light-year. To compare, Proxima Centauri, the closest star to our Sun, is about 4.2 light-years away. So, by using the fastest way we can travel right now, the mission to the closest star would take 73,773 years.
This reduces the number of planets we can visit in our lifetime to only the ones we have in our Solar System.
How long will it take?
- 6.5 years to travel to Mercury
- 15 months to travel to Venus
- 7 months to travel to Mars
- 6 years to travel to Jupiter (or one of its moons)
- 7 years to travel to Saturn (or one of its moons)
- 8.5 years to travel to Uranus
- 12 years to travel to Neptune
- 9.5 years to travel to Pluto
Human progress has a geometrical trend. The higher we go on the technological tree, the faster we accelerate. It is absolutely impossible to predict, but maybe 200 years from now, we could be travelling at almost light speed. But space is vast. So vast we can’t even imagine. Near light speed will simply not work for us.
Which planet in the solar system is the most habitable?
In terms of habitability, there are a few objects in our Solar system that may fit the purpose of supporting human life. If we ever get evicted from our home planet, the top candidate to host is Mars.
Our red celestial neighbour is also our best chance of colonizing another planet. The close distance (in space perspective) makes it the most easily accessible. Of all the planets in our system, Mars’ climate is closest to ours.
- There is underground water that can be extracted.
- There is enough sunlight, so that energy can be harvested.
- The day/night cycle is really close to ours: a day in Mars lasts 24 hours, 39 minutes and 35 seconds.
- Although the atmosphere is a lot thinner than ours, it’s enough to give partial protection from cosmic and the Sun’s radiation.
- Gravity on Mars is 38% that of Earth’s. This is considered enough for the human body to adapt.
But this is where the good things end. The atmosphere is made almost entirely of carbon dioxide. The lack of oxygen makes it hard for humans to survive on their own. Another issue is the temperature – the average Mars temperature is about -55 C (-67 F). There are various plans how to terraform the atmosphere, ranging from sending algae to actually nuking its poles. But, this is a complex and lengthy process with doubtful results.
Although not planets, Titan, Enceladus (Saturn’s moon) and Europa (Jupiter’s moon) are also considered to be able to support human life. They have liquid water and a stable atmosphere and could already be hosts to simple life forms.
How to move to another planet in our solar system
- Contact a space agency. You’ll be surprised, but they are more than you know. Not all of them have the resources to send a human being to Mars (much less somewhere farther), but they’re your best bet to start this endeavour with a first step.
- Be in a top health condition. No one will let you board a space shuttle if your physical or mental condition isn’t stable enough.
- Have patience and a vision. Despite everything, it’s still very early to plan and expect results. It won’t be a breeze. It will be the hardest project our world has ever produced. It will take many years. So, as frustrating, as it may be, we would be lucky to even be observed.
Earth-like planets outside our solar system
The first planets spotted outside the solar systems are gas giants like Jupiter. The technical method used to detect them observed the periodic wobble of the star, which appears when a massive object is orbiting it. And, eventually, when the planet moves between us and the star, good enough equipment is able to “see” it.
Of course, gas giants are not a good example of a planet that hosts life. Not only is their environment incredibly hostile, but they also don’t have a solid surface we can step on (because they’re gas giants). But, the good news is, just like Jupiter, a gas giant has a lot of rocky moons in orbit. Many of which are the size of Earth, or even bigger.
What makes an exoplanet habitable
Unlike the planets and moons in the Solar System, we still cannot observe well the conditions on exoplanets. So, for now, to be able to mark a planet as habitable, it needs to meet the following mandatory conditions.
- Orbit in the habitable zone of its star. The habitable zone is a disc around the star, where the temperature is neither too hot, or too cold for sustaining life as we know it. The distance and scale of the habitable zone vary depending on the size, temperature, and age of the star. Whether it’s a moon of a gas giant, or a singular rocky world, like our Earth, the planet needs to be in the habitable zone at all time.
- Not be tidally locked. A few of the closest stars are red dwarfs and most have gas giants in orbit. This is great because these are the stars with the longest lifespan (up to 10 trillion years). But, they’re also the smallest and coolest stars, which puts their habitable zone very close (relatively to the distance Mercury has with our sun). This can easily cause the planet to be tidally locked – meaning one side will be too hot, and one side will be too cold. This makes life impossible. The planet needs to rotate.
- Have water. We can overcome the previous problem easily if the planes have a big ocean. This way, even if it doesn’t rotate, oceanic currents can distribute the temperature and create stability. Besides, we do need water to survive.
Additional preferable conditions:
- Have oxygen.
- Have an ozone layer.
- Have a magnetic field.
On Earth, these three things have saved us countless times from the deadly solar radiation (including right now, as you read this article). But, by the time we manage to pull our civilization out of our cradle, we might have the solutions to artificially protect our new home.
Exoplanets in the habitable zone
Since the Kepler Spacecraft started working, we are finding more and more exoplanets orbiting other stars. Here is a list of the most promising examples.
- Kepler-186f, 490 light-years away and slightly bigger than the Earth.
- Gliese 581g, 20 light-years away and three times bigger than the Earth.
- Gliese 667Cc, 22 light-years away and 4.5 times bigger than the Earth.
- Kepler-22b, 600 light-years away and twice as big as the Earth. Best thing about this one is that the parent star is almost identical to our sun.
- HD 40307g, 42 light-years away.
- HD 85512b, 35 light-years away and three times bigger than Earth.
- Tau Ceti e, 11 light-years away and twice as big as the Earth.
- Gliese 163c, 50 light-years away and seven times bigger than Earth.
- Gliese 581d, 20 light-years away, seven times as big as the Earth and as a bonus, has a sister planet with just as much potential.
- Tau Ceti f, at least six times as massive as Earth.
These are just ten of the most optimistic examples we could give, and with time, there will be more.
How to move to another planet outside our solar system
The first problem we need to overcome when it comes to moving to another planet outside the Solar System is distance. Each of the exoplanets is very far away, but how much exactly?
What is a light year?
Light is the fastest thing in the Universe. It travels at a speed of approximately 300 000 km/s. So, a light year is the distance light makes for a whole year. This means that in the most optimistic case scenario, we have to find a way to travel with the speed of light, and it will still take us 490 years to get to Kepler 186f. Feeling discouraged already? Don’t be. As you see, there are a lot of other options a lot closer in our star neighbourhood.
How do we get there
Even if we find a proper candidate that would take us less than a human lifetime to reach, getting to the closest one (Tau Ceti e), would mean we need equipment to bring not only people but also enough food, water, and energy to last everyone on board for 11 years.
And, let’s not forget, this isn’t just a huge road trip with lots of supplies. This is a trip going through the most dangerous environment in existence. The ship should not only have the right fuel to last 11 years but also the best protection from radiation and of course, it better be hermetically closed from every nook and cranny.
Because of vacuum.
Lots of innovations are needed to even start planning missions to exoplanets, and people are already working on it. Visit NASA’s official website for information on future technology development, and see all the ideas you might bear witness to in your lifetime.
And, let’s not forget all these preparations are only for the trip. But…
What happens after we get there
The supplies would need to last for more than 11 years if we expect the crew we send to the new world would survive after landing. Now, we can start colonization, and a new chapter of human history unfolds.
Can we travel faster than the speed of light?
Meet the Alcubierre drive. In theory, with its help, we would be able to travel at a speed even higher than the speed of light. Based on Einstein’s work in general relativity, this device can bend and move space itself around it, thus reaching faster than light speed. But that’s still just a theory unlikely to be proven in the near decades.
How much longer does the Earth have?
The Earth has existed for about 4.2 billion years. Just slightly younger than the age of the sun and the Solar System. And, considering where we’re heading, the Sun will start its doomsday expansion after about 1.7 to 3.2 billion years.
It’s actually a close call in geological times. As the sun expands, solar flares will become a lot more destructive than we know today, and with time all the water will evaporate. Later, the heat will be enough to melt mountains. And, by the end of the expansion cycle, the Earth will be engulfed in the star that once gave us life.
So, thinking about moving to another planet is not that bad of an idea. The good news is, we have enough time to sort out the details.