Astronomers have a keen interest in finding earth-like planets orbiting other stars. Their hope is that earth-like planets might harbor life. This hope is based upon the belief that life arose naturally on earth, that is, without a Creator. This worldview assumes that there is nothing special about the earth, so life probably develops wherever the conditions are right. Therefore, life ought to be common in the universe, if the conditions are right in enough places.
But just where are the conditions for life right? Until about twenty years ago, we didn’t know if other stars even had orbiting planets, but we now know that many stars have planets orbiting them. However, most of those planets are not the proper distance from their stars for life to exist. If a planet is too close to the star it orbits, the planet is too hot to have liquid water; if a planet is too far away from its star, it is too cold for liquid water.
Since liquid water appears to be an essential ingredient for life, any planet outside of a narrow habitable zone around its star where liquid water could exist would seem to be eliminated as a possible home for life. But there is far more required for life to exist on a planet. Planets in a star’s habitable zone must have the proper composition and size. Of about 2,000 planets so far discovered around other stars, none of them are suitable for life.
Even the type of star that a planet orbits is important. Massive stars are very hot and bright. Such stars emit large amounts of ultraviolet radiation. Ultraviolet radiation is harmful to life, but the earth’s upper atmosphere shields the earth’s surface from most of the sun’s modest ultraviolet radiation. However, it is doubtful that any atmosphere otherwise conducive for life could effectively shield a planetary surface from the large amount of ultraviolet radiation from a massive star. Furthermore, massive stars have relatively short lifetimes, far shorter than the billions of years usually assumed for life to develop in the evolutionary worldview. Therefore, evolutionary scientists assume that lower mass stars are the most likely candidates for having planets where life might exist. Of prime interest are lower mass stars similar to the sun. Astronomers call such stars solar analogues.
Over the past few decades, astronomers have attempted to identify solar analogues. Most solar analogues are unstable, meaning that their light varies. This is different from the sun, which appears to be nearly constant in its light. It’s not clear why the sun is unusually stable. Variations in a star’s output would cause changes in surface temperature on any orbiting planet. Most solar analogues vary by only a percent or two. Perhaps life could survive under these erratic conditions, but there is a more serious problem. Solar analogues tend to vary by changes in spot activity.
Of about 2,000 planets so far discovered around other stars, none of them are suitable for life.
The sun has spots—we call them sunspots. Sunspots vary in number over an eleven-year cycle. During sunspot maximum, solar flares are much more common. Solar flares produce large amounts of charged particles that rush outward from the sun. Charged particles normally stream away from the sun, an effect that we call the solar wind. Hence, outbursts of charged particles from the sun amount to a gust in the solar wind. These particles are dangerous to living things, but these particles can’t penetrate the earth’s atmosphere.
However, there is another problem: the solar wind can strip a planet’s atmosphere away. This is what most planetary scientists think happened to Mars’ atmosphere. The earth’s magnetic field protects its atmosphere by deflecting most of the charged particles from the sun. Mars has a very weak magnetic field at best, too weak to shield its atmosphere effectively. If the earth had a much weaker magnetic field, it too probably would have little atmosphere left. Because sunspot activity is related to magnetic phenomena in the sun, strong spot activity on a star probably is related to strong, stellar magnetic fields on that star as well as strong winds from the star.
In a paper recently submitted to the Astrophysical Journal Letters, a group of researchers reported on their study of the star κ1 Ceti (κ is the Greek letter kappa). The team measured the magnetic field of κ1 Ceti, and also estimated that its stellar wind is about fifty times that of the sun. This star is similar to the sun, having nearly the same mass, size, surface temperature, and brightness. However, the estimated age of the κ1 Ceti is about a half billion years, far less than the sun’s estimated age of 4.5 billion years (assuming an evolutionary worldview, of course). In many respects, astronomers consider κ1 Ceti to be a good example of what the sun was like in its infancy. More specifically, if the sun has evolved over billions of years, then it was much more active and unstable in the past.
No one believes that the earth’s magnetic field could effectively shield the earth from such a large flux of charged particles. Therefore, if the sun was ever similar to κ1 Ceti, the earth would have lost its atmosphere. It is not clear if any mechanism could have replaced the earth’s atmosphere once it was lost. If κ1 Ceti truly is a good example of what the sun was like in its youth, then the evolutionary view of life on earth may be in trouble. If κ1 Ceti is not a good example of a young sun, then the evolutionary view of the sun may be in trouble. Either way, there may be a problem here for the evolutionary worldview.
Or is it possible that the sun, κ1 Ceti, and everything else in the universe is far younger than most scientists think? Or is it possible that the sun is unique, purposefully designed for our existence, just as the earth is purposefully designed for our existence? If so, then this would explain the sun’s unusual stability.
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