The GeoChristian

The Earth. Christianity. They go together.

Life on Gliese 581c?

The headlines:

Science Daily: New Planet Could Have Life

Yahoo News: Potentially Habitable Planet Found

Scientists have discovered more than 200 extrasolar planets (planets orbiting stars other than our sun) since the mid-1990s, and the numbers will certainly continue to increase as instruments improve. In regards to suitability for life, a vast majority of these planets are too large, too hot, or too cold; this is called the Goldilocks problem. Today, astronomers at the European Organisation for Astronomical Research in the Southern Hemisphere (ESO) announced that they have discovered a planet that might be “just right.”

The planet orbits a red dwarf star named Gliese 581, and it has been given the name Gliese 581c. Red dwarfs are smaller and cooler than our sun, and 581c orbits within what is called the “habitable zone,” which is the region around the star where it is possible to have liquid water on the surface—neither too hot nor too cold. The astronomers believe it is one of three planets that orbit Gliese 581; the others are designated 581a and 581b. The telescopes we have are not powerful enough to directly view extrasolar planets, but the astronomers infer their existence by watching the stars “wobble” under the influence of the gravity of the planets.

How does this relate to life in the galaxy? It is widely believed among exobiologists—those scientists who speculate about life elsewhere in the galaxy (certainly not to be confused with UFO-ologists)—that in order to have life, one needs liquid water. If a planet is too close to its star—or too far away—then conditions are not right to have living organisms, at least not on the surface of the object.

It also needs to be made clear that these astronomers are not talking about intelligent civilizations on worlds like Gliese 581c. The universe might have an abundance of places that are suitable for bacterial slime, and Gliese 581c might be one of them. The conditions required for advanced life—anything more complicated than a Paramecium or Amoeba—are likely to be exceedingly rare in the universe.

My thoughts:

  1. The results are very preliminary. We don’t have any direct measurements of the planet’s temperature. If it has a CO2-rich atmosphere, it could still be too hot, even being within the habitable zone.
  2. In the future, as instruments become more powerful, it might be possible to analyze light from planet such as this. If spectrographic analyses indicate presence of both water and atmospheric oxygen, this would greatly increase the probability that there is life of some sort on the planet.
  3. I would not see the discovery of primitive life on a world such as Gliese 581c as having any negative theological implications. Everything from Genesis 1:2 on is very Earth-centered, and so the Bible doesn’t say anything one way or the other about whether life exists on other worlds.


Artist’s conception of a planet orbiting a red dwarf, from hubblesite.org

Grace and Peace

April 25, 2007 - Posted by | Astrobiology, Astronomy, Origin of Life

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