As the human population continues to rise, we must begin to think of alternative options for habitation. In the past 50 years, the human population has doubled from roughly 3.5 billion to 7 billion people, and is still growing at about 1.14% per year, roughly an increase of 100 million people per year. Therefore, space colonization may become necessary in the near future.
The natural first option is Mars. For years, NASA has been using rovers to navigate the surface of Mars to find signs of ancient life and water. A couple of years ago, signs of water in a lake were found on Mars by the rover Curiosity, which is a possible indicator of the past existence of microbial life. Ice has also been found on Mars in polar ice caps—which could possibly have liquid water beneath them. Yet, the possible existence of water is not enough to sustain life. The temperature on Mars is significantly lower than the temperature on Earth since it is further from the sun than Earth is. Also, the Mars’ atmosphere is thinner than the Earth’s atmosphere, which would lead to greater levels of UV radiation. Lastly, the distance is also a problem. While we may see Mars as fairly close, it is still around a six-month journey away from Earth with the technology that we currently possess. We are still quite a while away from having Mars as an option for space colonization.
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An artist's rendition of the
Kepler Space Telescope |
Scientists have also begun to look for planets that are similar to Earth that are farther away. The
Kepler Space Telescope has been vital to this practice as its mission is to find planets outside our Solar System. So far, it has been successful, having found about 1000 confirmed exoplanets. Some of these planets are fairly Earth-like. Some of these planets are fairly Earth-like and lie within their stars’ habitable zones, the zones where water can exist in liquid form. The Earth Similarity Index (ESI) measures how physically similar a planet is to Earth. Recently, the most physically similar planet to Earth was found. Kepler 438b was found to have an ESI of 0.88, which is very high compared to Venus’ 0.78 and Mars’ 0.64. Unfortunately, Kepler 438b is 470 light years away from Earth, so it may never be inhabited by humans. Other Earth-like planets are closer. Kepler-298d, Kapteyn b, and Gilese 832c have ESIs of 0.68, 0.67, and 0.81 and distances of 11.9, 12.7, and 16.1 light years, respectively, making them more viable options for possible habitation.
While space colonization may not be necessary for the conceivable future, it is still potentially useful to find Earth-like planets now. Additionally, it provides some possible insight into extraterrestrial life that could be existing on these planets. Who knows what is out there to be found?
- Kevin Li
