Dear ladies and gentlemen! Today I propose not to talk about a wonderful future, but about the fantastical present. In our youth (and maybe as adults too) many of us read the stories of Isaac Asimov, Ray Bradbury, Harry Harrison, Robert Sheckley and the Strugatsky brothers. Stories that took the mankind to the endless vastness of space, to colonization of distant stars and planets, to encounters with inhabitants of other worlds, which often looked very different from us, but frequently were endowed by the authors with human virtues, vices and passions. However, the conversation today is not about that.
In the recent years the media has been raising more and more frequently the following question: isn’t it about time for us, the earthlings, to leave our dirty and polluted planet and move to a new, clean place? Since our environmental and ecological situation becomes worse every day, and numerous initiatives aimed to preserve the nature in a somewhat bearable conditions for life does not bring any significant results, the above question, with all its immorality and technical complexity, is worth consideration.
Here’s what the experts say about this:
Prof. Didier Queloz (Didier Patrick Queloz) is a Swiss astronomer who won the Nobel prize in physics in 2019. Together with Michel Mayor in 1995, he discovered 51 Pegasi b, the first extrasolar planet orbiting a sun-like star, 51 Pegasi. He said that the idea of humans escaping our planet to live in other solar systems was “farfetched and unrealistic”. “I think this is just irresponsible, because the stars are so far away. I think we should not have any serious hope to escape the Earth,” Queloz said. “Also keep in mind that we are a species that has evolved and developed for this planet. We’re not built to survive on any other planet than this one,” he said. “We’d better spend our time and energy trying to fix it than trying to imagine that we will… destroy it and leave it.”
Professor Michel Mayor, who jointly accepted the physics award with Professor Queloz for the first discovery of an exoplanet orbiting a solar-type star, added: “If at some point Earth becomes inhabitable there’s no way to escape. We are linked to this planet. We do not have a plan B. We have to take care of the Earth.”
On the other hand, many people hold the opposite opinion. That includes the late cosmologist and theoretical physicist Stephen Hawking who recently passed away.
Hawking have said threats such as nuclear war and climate change are so serious, that humans may have to eventually leave the Earth in order to survive as a species. In his final book, Professor Hawking wrote: “We are running out of space and the only places to go to are other worlds… I am convinced that humans need to leave Earth. If we stay, we risk being annihilated.” In one of his final interviews, Hawking issued a warning to humanity about the existential threats we face and how our survival depends on colonizing another planet. “I have no doubt we will eventually find ways of crossing the immense distances of space in just a few years… One of our greatest strengths is embracing new ideas and evolving them into cutting-edge technologies… Our ingenuity will get us to Proxima b and in the next 100 years we will embark on our greatest ever adventure.”
Michio Kaku is an American theoretical physicist, futurist, and popularizer of science. In his new book, The Future Of Humanity, he argues passionately that our future lies not on Earth, but in the stars.
“If you take a look at evolution on Earth, 99.9 percent of all life forms have gone extinct. When things change, either you adapt or die. That’s the law of Mother Nature. We face various hazards. First of all, we have self-inflicted problems like global warming, nuclear proliferation and bio-engineered germ warfare. Plus, Mother Nature has hurled at the Earth a number of extinction cycles. The dinosaurs, for example, didn’t have a space program. And that’s why the dinosaurs are not here today.”
“On the other hand, we shouldn’t use this as an excuse to pollute the Earth, or let global warming run amok. We should cure these problems without having to leave for Mars or another planet, because it’s impossible to remove the entire population of Earth to Mars. We’re talking about an insurance policy — a backup plan in case something does happen to the Earth. I once talked to Carl Sagan (an outstanding American astrophysicist and science popularizer) about this, who said, “We live in the middle of a shooting gallery with thousands of asteroids in our path that we haven’t even discovered yet. So, let’s be at least a two-planet species, as a backup plan.”
SpaceX CEO, Elon Musk, has a similar opinion: “Colonization of new planets, starting with Mars, is crucial to the survival of the human species… An extinction event is inevitable and we’re increasingly doing ourselves in. The goal is to improve rocket technology and space technology until we can send people to Mars and establish life on Mars”
Jeff Bezos, Amazon founder, wants us all to leave earth — for good. “The Earth is finite, and if the world economy and population is to keep expanding, space is the only way to go.”
“People have always shown they will do what is necessary to survive,” says Therese Griebel, deputy associate administrator for programs at NASA’s Space Technology Mission Directorate. “If the Earth becomes unsustainable, there will be a reason to go somewhere else.”
Well, the opinions of the leading scientists and the powerful people, are clear. And what do our experts think about that and what do you, our readers, think about that? Should we save Earth or leave it?
Dmitri Burshtyn: Humans are just one of hundreds-of-millions of species of living creatures living on Earth. For the sake of our own convenience, profit, or simply laziness, mankind consumes more and more resources of the planet, ignoring everything, destroying other species living on the planet by millions! Having spoiled his own habitat with such a consumer attitude, humans begins to look for a way to move to some other planet, to do the same there?!
This is a personal view of the situation. And now, let’s take a look from the point of view of technological capabilities that mankind has today:
To date, we do not have a launch vehicle capable of delivering people to the moon, not to mention Mars or other planets. Unfortunately, in this aspect, humanity was “officially” degraded: for example, the Saturn V rocket, which fifty years ago delivered the first astronauts to the Moon, is more than three times more powerful than the most powerful modern rocket (Falcon Heavy from SpaceX).
In addition, from the point of view of the technology used in rocket engines, we have not made much progress either – liquid-fuel engines (on kerosene) are used in most rockets flying today and planned for the future. The most advanced rocket engines use liquid hydrogen as a fuel (however, this technology is also 50 years old – as an example, the engines of 2nd and 3rd stages of Saturn V).
Today we use three types of engines for space flights: solid rocket engines (usually used as boosters at launch), liquid fuel rocket engines (used at all stages), and ion engines. Each of these engines has fundamental limitations.
Solid propellant rockets have a great thrust (the force pushing the rocket in the direction of movement), but a very small specific impulse (an indicator of the efficiency of fuel consumption – the greater the specific impulse, the less fuel must be spent to get a certain amount of movement). In addition, after ignition of a solid-propellant rocket, the process cannot be stopped, the engine runs continuously until all fuel has burned away (usually 3-4 minutes for the largest rockets).
Liquid-propellant rockets also have high thrust (but less than solid-fuel ones), and a small specific impulse (but bigger than solid-fuel ones). The liquid-fuel engine can be turned on and off several times. Because of a low specific impulse more than 90% of the starting mass of chemical rockets (solid and liquid) is the fuel needed to bring the payload (<5%) to Low Earth Orbit (LEO). It is acceptable this way to lunch into orbit small satellites (for example, communication satellites), weighing several hundred kilograms. But for the lunch to orbit interplanetary ship weighing hundreds of tons (together with the fuel necessary for an interplanetary flight) – this becomes almost an impossible task.
In addition to the technical complexity of building a super heavy-lift rocket, the cost of such a launch must also be taken into account – for example, the “cheap” launch of SpaceX super-heavy rocket into space costs $ 1.2 billion!
Ion engines are very efficient (large specific impulse), but they have very little thrust – millions of times less than chemical engines. Therefore with the help of ion engines it is impossible to lift a spacecraft into orbit, and they are used as auxiliary engines for correcting the orbits of satellites. Even starting from space, such an engine is too weak to deliver a mass of more than several hundred kilograms to Mars in realistic time – such a flight will take hundreds of years.
So in the foreseeable future (the next 50-100 years), mankind does not have the technology to deliver a large group of people and goods, not only to Mars or other planets, but also to the Moon.
It should be taken into account, that in outer space, on Mars and on the Moon, there is no Earth’s atmosphere, the ozone layer and the Earth’s magnetic field that protect us from the solar wind, harsh ultraviolet radiation and cosmic rays. The development of such technologies, as well as the building of a habitable and autonomous colony (including the construction and development of infrastructure), will take tens (if not hundreds) of years and unimaginable amounts of money. Thus, the establishing of a fully autonomous colony on another planet in the foreseeable future is an utopia.
Regarding fixing the environmental situation on Earth, the situation is completely different compared with flights to other planets. All the technologies needed for the complete cessation of carbon dioxide emissions into the atmosphere and industrial waste into rivers, for the safe disposal of waste (plastic, etc.), reforestation and the economical use of water resources, exist and are commercially available. Some examples: solar panels and wind generators for electricity generation, filtering and harmless disposal of carbon dioxide and organic waste (for example, see the “Waste to Energy” program), plasma gasification of any (including toxic) waste. Ocean Cleanup has developed a technology for collecting plastic waste in the ocean without compromising flora and fauna. For the economical use of water resources, drip irrigation technologies, desalination of sea water using reverse osmosis, and the extraction of clean water from condensate in the air have long been used.
Perhaps the cost of some of these technologies is still high, however, even in its current form it is ten times cheaper than creating an inhabited base on the Moon or on Mars. According to NASA estimates, a manned flight to Mars of a crew of 3-4 people will cost about $ 60 billion. On the other hand, according to UN reports, a complete cessation of СО2 emissions into the atmosphere will cost $ 60 billion.
So, the conclusion is: the only (at least for today) way for mankind to survive, is to fix the ecological situation on Earth using existing and accessible technologies. Relocation to another planet in the foreseeable future (50-100 years) is technically impossible!
Leonid Livshits: I absolutely agree with Prof. Queloz and Prof. Mayor. One sees what is going on with the weather breaking records every day and with Australia’s fires. I suppose that our only chance is to recall that humanity is not a superior king of the Earth and we are only one of millions of the species that live on Earth; to recall that the Earth is not a toy and not a laboratory. That our Earth is a living organism that is much stronger and wiser than we are. That we will admit to ourselves that the Earth may easily destroy the pathogenic parasite, which we know as “Homo Sapiens”. That our planet continuously hints us about that with periodic (and still relatively mild) earthquakes, typhoons and other cataclysms.
For someone, my suggestion will look strange, but we need to apologize to our planet. Together and everyone, without mutual insults. Everyone is to blame, both young and adults, politics and ordinary residents, regardless of gender, nation and religion. And then, we will start to clean up the garbage that we produce (at least!).
Of course, we may speculate about star flights. We might think about creating new underground or sea-bottom civilizations (both projects will probably be more real and cheaper compared to the space dreams). Nevertheless, I’m sure that we, humanity, have no future without our native planet.
Samyon Ristov: Why not to do both? Our eyes will always be directed towards the stars. We will always dream about them and work hard to reach them. First, we reach them with our eyes, then with robots, and finally, by ourselves. We are an exploring race. We explore the universe with our mind, our technology, our science and finally, by going where no man has gone before – it’s unstoppable, it’s just who we are and always has been.
But why not to combine it with saving Earth? Think about what we will benefit from it. As an old saying claims, “necessity is the mother of invention”. To save earth and by that, I mean saving all life on earth together with the people, we will have to develop new and amazing technologies, that now we don’t even dream about. Technologies for renewable energies, cleaning and reusing, monitoring, process control and more. Now we can think about solar panels, electric cars and rechargeable batteries – what technologies we can’t even imagine at the moment? What a great challenge it is. We will have to invest in science and learn about ecology, biology, climate, geophysics and many other fields that seems unrelated or not even exist yet.
Finally, we will have to modify our economy, politics, psychology and society. With all that, we will learn to treat life better, and treat ourselves better. Our greatest reward will be: to live without fear. Without the fear of extinction, of exhausting all natural resources, of uncontrollable economy, of hunger or upsetting the balance in nature.
With all that, our exploration and expansion to exoplanets will be much healthier, and we will reach them more mature, with better understanding of the technology, science and culture that are needed to live well in a new world.
Featured image by Mystic Art Design from Pixabay