Life-friendly zones in the galaxy? 09.30.11

With all the changes happening in the sciences lately, it is no small wonder that astronomers are beginning to re-think the “big picture” in their theories. For centuries, humans have wondered about the possibility of life elsewhere in the universe, and since the advancement of space technology, the hunt has become ever more insistent. Yet, with each little hint of the possibility of life, one or more factors always seem to be missing. Some astronomers are now beginning to reformulate their search plans and not look just for other solar systems elsewhere, but try to determine if there are specific areas throughout our galaxy that are more life-friendly.

In every solar system, depending on the class of the central star(s), there is a certain distance away from the center that is the most temperate area for supporting life as we know it. This zone is usually referred to by astronomers as the life zone, “habitable zone,” or even the “Goldilocks zone,” because it is not too hot or too cold. For instance, in our solar system, Mercury and Venus are much closer to our own sun, and as such experience much higher average temperatures year-round. Jupiter, Saturn, Uranus, and Neptune are all much, much further away from the sun than Earth, and are all much colder. Astronomers are still very hopeful about the possibility of life on Mars.

Image credit: NASA/JPL-Caltech/ESA/CXC/STScI.

So, if there is a specific life zone in every solar system, does the same rule apply for galaxies? Some astronomers are beginning to believe so, arguing that the centers of galaxies tend to be much more metal-heavy, which is much more conducive to planetary formation, so the odds are in favor of a planet forming with life on it. The flipside of the argument, however, is that the centers of galaxies also tend to be home to more supernovae. While all the constant light would be annoying, any life on planets in the galactic center would have to worry about much more serious problems like ozone depletion and literally having the planet fried by all manner of ray emissions from the multitude of stars. For now, the researchers will continue to scan the center of our own galaxy (pictured here) for more evidence and see how their theories unfold.

Credit: SPACE.com.