Dr. James Pierce's

Favorite Quotes from Life in the Universe Essays:

— Habitable Zone —

Every term, each student in my Astronomy 115 course (Life in the Universe) was assigned to write an essay giving his or her opinion on the following question:

"Do extraterrestrial technical civilizations currently exist in our Galaxy?"

This group of quotes concerns habitable zones. (The typos and misspellings are real, but they are not mine.) The material is presented here without comment; you will have to make up your own.

    Essay Quotes: Habitable Zone

  1. What this is referring to is the distance a planet is from its star, not to far away that it water, assuming that this planet is earth like and has water which is a key role in life, can freeze and distinguish life and not to close to make the surface temperatures too hot that would also distinguish life.

  2. Habitable zones are very small compared to the size of the galaxy, therefore the planet must sit just right in the galaxy or it is ruled out automatically.

  3. The problem with water is that scientists have struggled to find water on any planet, let alone a planet in a habitable zone.

  4. For the galaxy of a whole, it would need to have a lot of circumstances for it to happen. It would first have to be a continuously habitual zone of a star.

  5. To be in a CHZ, the planet needs to be close enough to their star to keep it warm and far enough away from the star so it isn't too warm, but not too far away that it becomes a complete icicle.

  6. There is also the danger of habitable zones which could shorten the existence of planets that are terrestrial.

  7. This area, known as the habitable zone, is fairly small in regards to some planets.

  8. Since stars are living, the habitable zone is always changing.

  9. The habitable zone is right in the middle of all the zones, and it is very likely that there are a lot of stars with such zones.

  10. I feel that all of these stars, which are in the same habitable zone as us, have the conditions that we've had and are just as conducive to intelligent life.

  11. There are so many star systems nearly identical to ours that are in the same habitable zone as us, that it wouldn't make any sense that at least one other system wouldn't form intelligent life in the same way as we did.

  12. The likelihood of a planet orbiting the right type of star in a continuously habitable zone and having the appropriate time for each stage of life to develop is extremely improbable.

  13. Four scientist by the names of Huang, Hart, and Kasting et al all have there own theories of where the habitable zone can range from but all of the scientist came about that a habitable zone that life can succeed is around .7 to 1 AU (Astronomical Unit) Just like the distance from the sun to the earth. This giving an example that is there is other life forms out there like us that this is where the best bet will be that they will exist.

  14. The star needs to have a habitable zone that is capable of harboring life.

  15. The habitable zone of a star is between the distances from the star where water boils to the distance where water freezes.

  16. The number of planets that are within the habitable zone and are a G, K, or M stars is very small.

  17. With that said we need to find the continuously habitable zone which will be somewhat in the middle of the spectrum. That way as the star gets older the radiation from it will not affect the planet as much because it is further away giving it more time for that technical civilization to form.

  18. The planet would have to be located close enough to the mid temperature star where it could get the effects of the star such as heat, and light, however far enough away so it wasn't to hot, or bright, meaning it would have to be in a safe habitable zone, and have a source for tidal locking.

  19. The role of the habitable zone is to keep a planet habitable, assuming that the planet has all the necessary components to sustain life, for example being outside the habitable zone closer to the sun any water on the planet would be avaporated and any planet farther away from the planet outside of the habitable zone the water would freeze.

  20. Since the CHZ is so narrow, and few stars and planets can form within it, the chances are rare that a technical civilization will exist.

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Created May 12, 2013; last modified March 19, 2021
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