For a long time there has been a latently held view that our Sun was special in that it was the only planet so far found to harbor life nearby. It had seemed that Earth was lucky to have developed life – through whatever means you choose to herald as the “right one” – in part due to its stellar parent.
However, according to a new study from scientists from the Australian National University (ANU) in Canberra, the nation’s capital, overall, our Sun is nothing more than a random chance at having harbored life.
Charles Lineweave, with colleagues José Robles and others, analyzed 11 features of the Sun against other stars, to see whether our star was anything special. "The Sun's properties are consistent with it being pulled out at random from the bag of all stars," says Lineweaver. "Life does not seem to require anything special in its host star, other than it be close."
Previous studies of our Sun’s specific characteristics had concluded that it was unusual amongst stars. For instance, some pointed to the fact that the Sun has a higher mass than average, an atypical property that some believed counted towards the reason that Earth developed life.
But these early studies only looked at a small number of solar features, focusing on one or two facts, rather than a broader look. Lineweaver posits that there was a tendency to sort through the statistics, and in order to rationalize why life existed on Earth, pick out the outstanding ones.
"You can mistakenly come to the conclusion that the Sun is 'special'," Lineweaver told New Scientist in an article that appeared last week.
Lineweaver and Co. looked at a variety of features, including the Sun’s mass, age, rotation speed and orbital distance from the center of the Milky Way. They then compared these statistics to other stars to see whether our Sun stood out at all.
It did, but only in two areas. First of all our Sun is more massive than 95% of nearby stars, and its orbit around the center of the Milky Way Galaxy is more circular than 93% of other neighboring stars.
But Lineweaver once again points to the fact that, overall, when all of the 11 categories are taken in to account, the Sun is relatively ordinary. Robles’ team calculated that there would only be a 33% chance that a star selected at random could be “more typical” than our Sun.
What may or may not be a leap from their research, is their last conclusion that there are probably no remarkable categories that a star must meet to harbor a habitable planet, other than the obvious existence of a planet living in the star’s habitable “goldilocks” zone.
What’s the goldilocks zone? It’s that distance from a star where the temperature is not too hot for life, and not too cold; it’s just right!
Joshua Hill, a Geek’s-Geek from Melbourne, Australia, Josh is an aspiring author with dreams of publishing his epic fantasy, currently in the works, sometime in the next 5 years. A techie, nerd, sci-fi nut and bookworm.
