Human Expansion into Space
Human population on earth has exploded over the past few centuries; it has gone from a small collection of hunters and gatherers to a globally connected race of over seven billion people. Even though humans have gotten so numerous and expanded so far, we are lucky to have gotten to this point at all. Earth is threatened all the time by events that could end the human race as we know it. Things like global war, famine, natural disasters, manmade disasters, asteroid hits, hostile extraterrestrial life, or other countless things that could bring an end to humans. Currently the entire population is on one planet, this means if one of these events come to pass humans could become extinct. With the threat of mass extinction imminent, the human race needs to expand past Earth and colonize other earth like planets in the Milky Way. With this expansion humanity is not just on one world and could survive after a disaster on earth. In order to expand scientists will have to solve three main problems: finding a planet suitable for colonization, the technology needed in this undertaking, and the political red tape.
The first main problem in colonizing space is finding a suitable planet to colonize. According to (Villard, 2011) in “Hunting for Earthlike Planets,” there are several steps that scientists use to look for a planet with the possibility of supporting human life. The first and most important step is finding a planet within the goldilocks zone or habitable zone, this zone is the correct distance from a planet’s sun to allow liquid water on the surface. Once a planet is found in that zone, scientists then need to run a spectroscopic analysis on the atmosphere, this test uses light reflecting off the planet to see what gasses the atmosphere is composed of. This will show the scientists if the air on the planet is breathable to humans by comparing it to what Earth's atmosphere reflects. If the found planet’s atmosphere looks promising, scientists then use a test called the wobble effect to see if the planet is close to being the same size as earth. The wobble effect is comparing how much influence a planets gravity has on its star when it orbits, the more wobble of the star the bigger the mass is of the planet. This is important because if the planet is too big or small humans cannot live in its level of gravity, as humans are evolved for the level of gravity on earth. For example, if it is too big of a planet then it would be like us walking around with an elephant on our back. As stated by Shiga (2008) other important factors to a planet’s ability to sustain humans are if the planet has the correct amount of rotation angle, moons and rotation. These factors are important because they all affect the climate on the planet. If a planet’s rotation angle is too big it would cause extreme seasonal weather, making long-term colonization difficult. If a planet has a moon, several moons, or none at all is important because moons have a tidal effect on a planets oceans and liquid core. This effect is one of the reasons Earth’s climate is so good, the tidal effect on our liquid core keeps the liquid metal heated up which intern keeps volcanoes and continental plates moving. Without this movement, our atmosphere would slowly bleed of into space and earth would become like Mars. Rotation is important because without it one side of the planet would always be in the light and one always in the dark. This would make an unstable climate, extreme weather and very little amount of area suitable for human habitation.
Once scientists find a planet that is suitable for colonization, they then need to figure out the best way to send an expedition to it. As Folger (2013) explains, the main problem in interstellar travel is the distance. The closest star to Earth's solar system is Proxima Centauri; this star is a mind-boggling 24-trillion miles away from earth. With the fastest spacecraft humans have ever built, the Helios 2 probe which travels at 157,000 miles per hour it would take more than 17,000 years to reach it. With the possibility of the planet chosen being several times further away than that, scientist are going to have to develop a new technology to get there. Currently, scientists are in the early stages of developing a few deferent ideas of spacecraft that possibly could get humans that far. The first idea is a solar sail ship; this uses photons emitted by stars to push a light reflective sail to great speeds. The main problem with this type of ship is the size of the sails needed to push it that fast; it would take a sail the size of Texas to get the ship to the edge of our solar system. One way to improve this design is to augment natural star power with heavy duty lasers, if scientists can develop a practical way to generate and store power efficiently for a long term journey, the spacecraft could achieve much greater speeds and distance. Another, spacecraft design that could make the trip feasible is a fusion reactor. These reactors use the same combustion as stars and are far more efficient than conventional chemical rockets used today. Although, these types of spacecraft may significantly lower the time needed for such a long trip, there is still the problem of putting humans in the craft. As Andrews (2012) explains, humans are a fragile race, we require vast amounts of resources to live. An interstellar expedition would require lots of people to be able to be achievable, which intern requires a huge spacecraft, heavy amounts of shielding to protect the ship and crew, the ability to grow enough food to feed the population, a way to clean the air they breathe, all the equipment needed to colonize a planet, enough space to negate the fact that they are stuck on a spacecraft all by themselves trillions of miles away from home, and all the other conditions humans need to survive.
If scientists can solve the problems of what planet to go to and how to get there, the biggest hurdle to the expedition would be political (Andrews, 2012). The first and most important political problem is money; an expedition of this size has estimated low-end cost of over 4 trillion dollars. The mission planers would have to convince not just one country's people, and government but the entire world that the trip is worth the price tag. Even if they give people all kinds of studies and statistics showing how the expedition could help the world economy there would still be those that say the price tag is too high. Since, it is such a high price it could never be accomplished by one government, but would have to be a calibration of many. This calibration could be the downfall of the expedition, because as history has shown when many governments try to work together egos, and self-interest can cause the whole thing to crumble. If the money and political bickering are solved then comes social issues such as religious and other extremist groups (Corley, 2012). If these groups decide the mission goes against their beliefs, they could be big trouble for the expedition, and they could cause mass riots, suicide bombers, or sabotage the trip. Then there is the social problem of who gets to go to the new world, and who picks the people going. This selection process could leave bad fillings in people not picked which intern can hinder the success of the mission. So there would have to be a fair and just way to do the selections. If the mission planners can convince the world this mission is the most important undertaking humanity has ever done, it will have a chance to succeed.
The political, technical, and destination problems to expanding past Earth are not easy to solve, but it can be done. If all of humanity works together and takes it one step at a time, working in mutual interest, we can save ourselves from becoming extinct when Earth is struck by disaster. Not only can we save ourselves from this fate, but by working together to become a multi-planetary race humanity can grow and prosper from the technologies developed, the learnt ability to work together, and mutual goals it would take to accomplish the expedition. Humans are survivors that is what we do, if we become a multi-planetary race we will have the ability to survive for millions of more years. Reference
Andrews, B. (2012). How humans will travel to Alpha Centauri. (cover story). Astronomy, 40(7), 22.
Corley, A. (2012). Where in the Cosmos Will We Explore?. New Scientist, 213(2854), 44-46.
Folger, T. (2013). CRAZY FAR. National Geographic, 223(1), 68.
Shiga, D. (2008). Back to the drawing board. New Scientist, 199(2683), 36-39.
Villard, R. (2011). Hunting for earthlike planets. (cover story). Astronomy, 39(4), 28.