Saturday, May 24, 2008

A blow to the "Rare Earth" hypothesis?

Sun's properties not 'fine-tuned' for life

"The Sun's properties are consistent with it being pulled out at random from the bag of all stars," says Charles Lineweaver from the Australian National University (ANU) in Canberra. "Life does not seem to require anything special in its host star, other than it be close."

Some previous studies of the Sun's vital statistics have concluded that it is unusual among stars, for instance, by having a higher mass than average. Such atypical properties might somehow help explain why the Sun seems to be unique, as far as we know, in having an inhabited planet.

But the earlier studies only looked at a small number of solar features, such as its mass and iron content. Lineweaver suspects there was a temptation to sift through the Sun's properties, then focus on the outstanding ones while ignoring the normal ones.


intense said...

The "rare earth" hypothesis is not necessarily discredited by the factor of the sun--the moon's contribution to stabilizing our planet's oscillation and acting as a meteoric shield are probably more important.

The combination of our sun's relative stability, the moon, and our orbital position together are major factors, among others, in making earth, I suspect, a rather rare place for complex, intelligent life to have evolved and to be able to exist.

kcotae said...

Planet's don't need a "sun" for life. (maybe not as we know it) Just some form of internal heating caused by gravity, magnetism or vulcanism. Mind you it certainly helps to speed up "evolution" if a star is present.