By Kevin Biggiani
In 1995, the first evidence was discovered that other stars have planets, just as our sun does, according to The Planetary Society, founded by well-renowned astrophysicist, Dr. Carl Sagan. Planets that orbit stars outside of our solar system are called exoplanets. Today over 4,100 exoplanets have been discovered and catalogued in the NASA Exoplanet Archives maintained by the NASA Exoplanet Science Institute.
You may have heard the Earth is located in what is affectionately called the Goldilocks zone — not too hot, not too cold — where the surface temperature is just right for liquid water, essential for life to develop and thrive, to exist. This zone is not necessarily any confirmation that life exists, since the planet’s atmosphere is also a vital factor. A planet’s mass is also important, and if it is rocky or just a ball of gas or ice. But did you hear, as reported by Space.com, a November 2013 study using data from the Kepler Space Telescope suggested that one out of every five sun-like stars in the galaxy has a planet the size of Earth circling it in this Goldilocks zone? Every day we get closer and closer to possibly finding out we have distant neighbors.
The New York Times reported that astronomers believe as many as forty billion habitable Earth-size planets could exist in our galaxy, though seeing them and then reaching them might be a different story. The question then arises: is there extraterrestrial life on these exoplanets? If yes, what might this life look like?
Astrobiologists, concerned with the origins, early evolution, and the future of life in the universe, are constantly looking for life on other planets. But what exactly are they looking for? Life could be anything from spacecraft-flying extraterrestrials to bacteria. How will they know when they find it?
Astrobiologists struggle with imagining only from what they know has transpired here on earth, and that may not be enough to understand what may have happened on other planets under different conditions. If they just extrapolate from what has happened here on Earth, their vision may be too limited. Every AP Bio student knows all the important molecules in our bodies are made up of carbon atoms. However, Science ABC reminds us Dr. Sagan’s warning about carbon chauvinism. He believed that limiting our imagination with the assumption that alien life would resemble life on Earth would be a terrible mistake.
Astrobiologists will need to think beyond the known and open their minds to whatever could be. Or maybe we will just get lucky and our distant neighbors will find us instead.
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