Earth-like planets may be more rare than thought

August 2, 2004 | Source: Nature Science Update

We could be alone in the Universe after all. Martin Beer of the University of Leicester, UK, and co-workers argue that our Solar System may be highly unusual, compared with the planetary systems of other stars.

They suggest that other planets (which are detected from the wobble that they induce in their own sun’s motion) were not formed by the same kind of process that produced our Solar System (coalescence of planetesimals), but by condensing directly out of the gaseous material around stars. So they might not have smaller, habitable companions.