Today, Earth is a very accommodating and hospitable place for us to live. Temperatures are just about right. There is more than enough oxygen for us to breathe. Pure drinking water falls from the skies. Food grows on trees. For what more could we ask?
These near-ideal conditions are dependent upon our nearest star, the sun. Our understanding of solar physics and astronomical observations of other stars tells us that since its formation the sun has grown 30 percent brighter. Over the course of time this increase in brightness will continue. It is projected that when it becomes only 10 percent brighter than today the increased radiant energy reaching Earth will have vaporized the oceans, creating H2O greenhouse conditions that will raise temperatures by several hundred degrees, killing off all plant and animal life.
Because the sun burns through 600 million tons of hydrogen per second, it has already consumed almost half of its hydrogen stockpile. Further down the road, after this supply of hydrogen has become depleted, the sun will become a red giant star, rapidly burning through its limited accumulation of helium. The brightness of the sun will dramatically increase in nearly a dozen outbursts over the course of a few thousand years, peaking at 10,000 times its current brightness and ballooning out to more than 250 times its current diameter, swallowing all of the inner planets, including Earth.
As the helium becomes exhausted the sun will unleash its outer shell as a massive tsunami of particles and ionized gases that will sweep across the remaining solar system, forming a planetary nebula. Finally, the core of the sun will collapse, becoming a faint, tiny, white dwarf star that will slowly fade to black.
Although our home planet may be a paradise today, hundreds of millions of years into the future it will become a hell. And billions of years later, it will cease to exist. There will come a time, then, when we must choose between a destiny among the stars or extinction. To be, or not to be? That will be the question.
At this moment we are not totally prepared to embark on an interstellar escape. Fortunately, we may have millions of years to develop the required technologies and marshal the enormous resources needed for a mass emigration to another solar system.
What are the beginning steps that we should take now in order to make sure that we will be ready when the time comes?
The first step is to make sure that everyone understands the unfortunate fate that awaits this lovely planet — and us if we fail to act. The potential extinction of the entire human race, no matter how far into the future, is no laughing matter.
The second step is to take reasonable precautions to guarantee that mankind will continue to thrive on this planet for millions of years. If the entire human race should perish tomorrow night, then starships will probably not be happening anytime soon. We should therefore minimize the risk that our future could be jeopardized by warfare, diseases or natural disasters.
“Because starships will not be ready to go for many centuries and interstellar voyages may last for thousands of years, we will want to get started sooner rather than later, initially allocating a small but steady fraction of the space budget to identify the most promising engineering approaches and performing early proof-of-concept experiments when affordable.”
There are a variety of precautions that we could take.
In theory, we could carefully screen our political and military leadership to disqualify mentally unbalanced, destructive or irresponsible individuals.
We could prepare compartmentalization procedures that could be implemented whenever a deadly epidemic threatens to rapidly spread throughout the world.
We could accelerate the search for near-Earth asteroids and comets in order to provide advanced warning of threats. And if required, we could assemble an arsenal of kinetic and/or thermonuclear warheads that could be used to deflect killer asteroids.
If worst comes to worst, we could construct underground shelters that would protect much of humanity from almost anything that nature (or man) could throw at us.
The third step is to align our space program to this long-term objective so that we will have the knowledge and technologies required to someday reach the stars and thrive, comfortably, when we arrive. A consistent direction, stable headcounts and affordable budgets will be essential to achieve such challenging long-term objectives. In order to be able to support this sustained effort, we will need a productive economy and an educated workforce.
The first goal of our space program should be to conduct a search, using advanced telescopes, for the most promising nearby solar system for the future of mankind.
The second goal should be the development of closed-loop life-support technologies that can keep humanity alive and well on long interstellar voyages. These technologies also could be utilized on manned space missions to Mars and could even help failsafe humanity on this planet.
Because it is not at all likely that a warm, moist, green, oxygen-rich twin of Earth will be within our reach, the third goal must be learning how to live under less-ideal conditions, such as on the Moon. We should establish manned outposts on the Moon and Mars where we can develop the expertise to efficiently manufacture everything that we need from local planetary materials. Over the course of hundreds of years, as these outposts grow, they will become second homes within this solar system for humanity.
The final and most challenging goal of our space program will be the development of interstellar spacecraft for transporting humanity to safer places when this solar system turns hostile. Although this will not require faster-than-light travel or other violations of physics, the development of this technology will not happen overnight. Because starships will not be ready to go for many centuries and interstellar voyages may last for thousands of years, we will want to get started sooner rather than later, initially allocating a small but steady fraction of the space budget to identify the most promising engineering approaches and performing early proof-of-concept experiments when affordable. The first application of this technology will be for unmanned interstellar probes that will conduct close-up reconnaissance of nearby solar systems.
Today we live in a culture that is so overly obsessed with the current moment that we are reluctant to think beyond the next few months or years. Perhaps our dystopian aversion to the future is a madness left over from the Cold War. In any case, this stellar challenge will require us to begin seriously planning for our future. It should also provide us with a greater sense of purpose and a more positive outlook. Because concrete steps will be taken to ensure that really bad things will never happen, we can rest assured that the story of mankind, unlike the tragedy of Prince Hamlet, will not come to a premature end.
Nelson Bridwell is a senior machine vision engineer working in manufacturing automation.