Alien Life Forms

by Jeanette Cain

More articles in SETI

Does ET exist? If alien life forms do exist, would we recognize them as having life? Intelligent life may not resemble humans, or other forms of life that we consider life. But, the odds are in favor of intelligent life on other planets and stars.

With the availability of suitable parents, life may certainly exist. The building blocks of life, as we know it, are hydrogen, oxygen, and carbon. These building blocks are common elements in the vastness of space too. The problem: alien life forms may not resemble humans or other familiar life forms.

Evolution is still hotly debated on Earth. According to the theory of evolution, many varied and strange routes may be taken by a species for the purpose of surviving. Life on Earth is probably the biggest single mystery facing mankind.

During the developing of the planet, environment played a major role in the development and survival of a species. For survival the environment had to be "just right." Do you remember the fairy tale of The Three Bears? On the third try Goldilocks found the porridge "just right." This is similar to adjusting to the environment. The "just right" conditions would include staying warm, having a suitable atmosphere, and water, which helps in forming chemical reactions.

The interstellar distances between galaxies and universes are phenomenal. the ability of intelligent life forms to communicate to other planets would need to have conditions that are "just right." Frank Drake, a pioneer in astronomy, laid out certain guidelines for researching extraterrestrial life forms in 1960.

The guidelines are listed below:

1. Stars need to be born at a rate capable of replacing the stars that die. (Earth's galaxy sees the birth of about ten new stars every year.)

2. A star will need to have planets on which life can exist.

3. The right stuff at the right time guideline: a planet of the right size needs to exist at the right distance from a star. This will create an environment that is neither too hot or too cold, but just right.

4. The planet will need to have life emerge from it.
5. The life that does emerge will need to evolve into intelligent beings.

6. This intelligent life form will then need to develop technologies that allow communication over the immense distances of interstellar space.

7. After the intelligent life invents these technologies, it needs to learn NOT to destroy itself with these technologies.

8. The natural disasters need to be seldom and far between to give this intelligent life time to evolve. Natural disasters refers to volcanic eruptions, comet and asteroid collisions on the surface.

After these conditions have been met, the next important step is having intelligent life in other parts of the galaxies, who have met the same criteria. Life is everywhere, only humans do not recognize all life as intelligent. Is the bacteria that causes strep infections intelligent life? For its world, it may very well be on the top of the food chain. Humans, however, expect something different when searching for intelligent life forms.


1. Couper, Heather and Nigel Henbest. Space Encyclopedia DK Publishing, Inc.: NY 1999

2. Editors. Secrets of the Universe. International Master Publishing: US. 1999