A Brief History
On April 17, 2014, the Kepler space telescope operated by NASA confirmed the existence of Kepler-186f, the first discovery of a planet of equivalent size to Earth within the “habitable zone” of another solar system. The newly discovered planet is in the solar system of a red dwarf star called Kepler-186, only about 582 light years away! (A light year is roughly 6 trillion miles.)
We know that at some point the Earth will become uninhabitable for human civilization. This eventuality may take hundreds of millions of years, or even billions of years, when our Sun goes super-nova, or sooner in the face of a cataclysmic cosmic event such as the Earth being struck by a sizable asteroid. An ice age or period of extreme high temperatures might also spell the end of humans on Earth. Meanwhile, overcrowding of people may create a situation where new worlds are absolutely necessary for society not to collapse. A massive nuclear war could make the Earth largely unfit for human population. In any case, the continued existence of the human race is by no means guaranteed, and there is nothing inevitable about us finding a new home.
Of course, the first places people look to find a new world for human life is within our own solar system. Alas, the other planets are too hot or too cold and lack the life sustaining features we need to survive. Colonizing Mars or the Moon means a very limited existence not much different than living in a deep underwater sea lab. Maintaining a large population of humans pretty much requires certain attributes of any potential new home on a distant planet or moon of a planet.
What are those requirements? A potential new home for humans must be roughly the size of Earth and of a similar density, or else the gravity there could make human movement impossible. A new world a bit smaller than Earth could be ok, but not bigger. This New Earth would also have to have adequate supplies of Oxygen and liquid water, while NOT having any other atmospheric chemicals toxic to people. The temperature must be within a range sufficient for humans to live and grow food, and the atmosphere must protect humans from ultraviolet rays. This potential haven must exist in the “habitable zone” of a solar system, that is, just the right distance from its sun to provide enough light and warmth without cooking humans. Complicating things even further, the soil must be compatible with growing human crops, as transporting large amounts of dirt across interstellar distances is waaayyyy ridiculous. This new Earth must not have organisms large or small that would kill off people in short order. Like Goldilocks looking for a meal that is not too hot and not too cold, and a bed that is not too hard and not too soft, the search for an appropriate New Earth is an intricate and complicated series of finding a serendipitous combination of factors that are all “just right.”
The next REALLY BIG problem with colonizing another planet is the distance from Earth. As stated above, the first planet our astronomers have found in the “habitable zone” of another solar system is 582 light years away. That means, if we could travel at the speed of light (we have no reason to believe we will ever be able to do that) it would take 582 years to get there. Even exploratory probes would take that long, probably too long to realistically either get people there alive or adequately explore the place before mounting an expedition. Some sort of teleportation or fantastical science fiction “warp speed” would be needed for such interstellar travel. Even the closest stars to our solar system are the 3 stars of the Alpha Centauri system, 4.37 light years away. The comparatively modest attempt of trying to get people to Mars is a major production, and Mars is a comparatively close 33.9 million miles at its closest approach to Earth in the last 50,000 years. The actual distance between Earth and Mars is variable as the orbits of both planets are not exact circles. At times, Mars is more than 60 million miles from Earth. For comparison, the Moon is only 238,000 miles away and going there is an incredibly difficult undertaking requiring enormous rockets to carry a relatively small payload. With current technology, it would take about 7 months in each direction to get to Mars and 7 months to return, meaning a minimum trip of well over a year, meaning a massive amount of food, water and Oxygen must be allotted for such a trip, meaning in turn a really big space ship. Our ability to launch something of massive size is limited to say the least. The spacecraft depicted in movies that are as big as cities could never be launched from the Earth, as they would have to be assembled in space. The sort of project sending mass amounts of people and mass amounts of provisions through space is not even in our distant future at this point.
At the risk of being pessimistic, we do not believe humans will ever colonize another planet, and will die out, becoming extinct, before such technology is available. Or we could be wrong? What do you think?
Question for students (and subscribers): Will mankind ever colonize a distant planet? Please let us know in the comments section below this article.
Your readership is much appreciated!
For more information, please see…
Popular Science. Popular Science The Future of Space Travel: Your New Ride to Space. POPULAR SCIENCE, 2017.
Tyson, Neil deGrasse, Charles Liu, and jeffrey Simons. StarTalk: Everything You Ever Need to Know About Space Travel, Sci-Fi, the Human Race, the Universe, and Beyond. National Geographic, 2019.
The featured image in this article, a size comparison of Kepler-186f (artist’s impression) with Earth along with their projected habitable zones, is in the public domain in the United States, because it was solely created by NASA. NASA copyright policy states that “NASA material is not protected by copyright unless noted“. (See Template:PD-USGov, NASA copyright policy page or JPL Image Use Policy.)