This is a side issue for the creation/evolution controversy, so just a few brief notes.
Evolutionists, typically, believe our solar system is just like millions of other solar systems, and fully expect to find planets circling other stars. Further, they believe that since they think life evolved quickly here soon after the earth cooled down, therefore we should expect life to be widespread in other solar systems as well. For this reason they are deeply interested in identifying potential extra-solar planets.
Creationists are a little more ambivalent. We don't "need" for this solar system to be the same as millions of others (i.e., it wouldn't shake us up if it turned out to be rather unique), and there is no plain Scriptural clue pro or con regarding whether planets exist around other stars. It is safe to say that most creationists believe organic life is limited to earth (see, for example, the ChristianAnswers.Net essay on this topic.) Regardless, life wherever it exists in this universe must be intelligently engineered and designed to exist. Overall, if our solar system was unique that would be a lot easier for creationists to accept than evolutionists, who often emphasize their belief that we are nobodies in an unspectacular section of one little corner of a vast universe.
Some creationists have suggested that if life doesn't exist around other stars, then there is no reason to believe planets orbit those stars either. However, I think it is fallacious to assume planets only exist for the purpose of supporting life. The simplest proof of this view is the existence of eight other planets and numerous satellites in our own system, none of which support life.
Have Planets Been Observed Around Other Stars?
The technology to directly see planets around other stars does not exist. However, scientists have attempted to look for extremely large planets, if they exist, by looking for a wobble in the motion of nearby stars. This wobble would be caused by the large planet (much larger than anything in our solar system) and the sun orbiting around their common center of gravity, which would be within the star's circumference.
The history of this search does not appear to be one of astronomy's greater successes. A number of claims have been put forth, followed by retractions, criticisms, and controversy. In at least one case it has been argued that the only thing wobbling was the astronomer's telescope, not the star it was viewing! In other cases claims remain unverified, or attempted verifications appear to have failed. As of this writing eight purported planets are claimed to exist around other stars, but this is disputed by critics who believe excitement over the idea of life on other planets (part of what I call "the Neato! factor" in the human element of science) is leading investigators to ignore other interpretations of the data.
A New Criticism
This morning the Pointcast network ran the following story from CNN, illustrating my point. The article, by Greg Lefevre, is titled "Is it a planet, or isn't it? Scientists disagree," posted at 10:22 PM EST, 2/26/1997. It describes the work of astrophysicist David Grey, who believes the wobbling stars are really pulsing stars. Stars go through a variety of cycles (such as the sunspot cycle), and some pulse (i.e., pulsars) on a regular cycle. Grey believes this explains the data better than a superplanet theory. Here is an animation of Grey's model.
Grey, who recently had an article published in the journal Nature, stated, "The planet [theory] simply cannot explain the new observations at all, period." That's a pretty strong claim. Time will tell which side is on the right track.
By the way, journalists are constantly referring to the possibility of life existing where these putative planets are found. This is wild speculation, because the presumed planets are absolutely terrible candidates for life regardless of what belief in origins you have. The example given in this article has an orbital period of only four days! By contrast our closest planet, Mercury, has a period of 87.97 days. This means that not only is the planet giant size (in order to cause the star to wobble enough to be seen), it also has to be virtually skimming the surface of the sun! That would make it pretty toasty for any critters on board.
I presume all extra-solar planet claims are similar, since the observers are looking for wobbles over a finite period of time and this requires a fast, tight orbit.
In summary, the continuing claims in the media of planets being discovered are interesting but premature, and they typically don't report claims debunking the earlier reports as well. This is giving rise to misconceptions (or "pre"-conceptions as the case may be) in the general public.
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