Solar System could be 'unique'

By Aussiegirl

If we are unique, then where have all those UFOs come from, and who -- or what -- is piloting them? Perhaps we are alone in the universe after all.

BBC NEWS | Science/Nature | Solar System could be 'unique'

Solar System could be 'unique'
By Jacqueline Ali
BBC News Online

The search for other planets like our own could be in vain.

The Solar System could be unique amongst planetary systems in the Universe, astronomers have announced.
New analysis by UK astronomers suggests our own planetary system may have formed in a very different way to those spotted orbiting other stars.

The findings suggest that one formation mechanism may not fit all planetary systems, as other astronomers have previously suggested. [....]

In the past 10 years, over 100 extrasolar systems (planetary systems orbiting stars other than the Sun) have been discovered from the wobble in their host stars, caused by the motion of the planets themselves.

But none of them seem to resemble our Solar System very much. In fact, these exoplanets have several important attributes that are entirely at odds with the Solar System as we know it.

Lead researcher Dr Martin Beer of the University of Leicester's theoretical astrophysics group, pointed out that much of the modelling done on the formation of planetary systems is based on our own one.

"But existing data suggests that the planets in the Solar System are truly different from other planets," he told BBC News Online.

If this is the case, Beer and his colleagues argue in their research paper, it is unreasonable to base our understanding of all planetary systems on the one around the Sun.

They go on to speculate that if the Solar System is unique, then the search for Earth-like planets around other stars may be in vain.

When compared to all known planetary systems, say the authors, our own is something of an anomaly.

This appears to suggest that there might be two entirely separate mechanisms of planetary formation at work, or - at the very least - that there are two extremes of a single formation process. [....]

"It will be another five years or so before we will be able to see systems like our own," he added. "At that point we will know whether the Solar System is truly different, or in fact very average."

"Nevertheless, the existing data leaves open the possibility that [our own planetary system] is quite unique compared to [others]. If this turns out to be true, then our current understanding of planet formation is unduly coloured by our intimate knowledge of the Solar System."