Explanation: How common are planetary systems like our own?
Perhaps quite common, as the first system of planets like our own Solar System has been discovered using a newly adapted technique that, so far, has probed only six planetary systems.
The technique, called gravitational microlensing, looks for telling brightness changes in measured starlight when a foreground star with planets chances almost directly in front of a more distant star.
The distant star's light is slightly deflected in predictable ways by the gravity of the closer system.
