This raises the possibility that planets like ours orbiting in habitable zones could be covered in oceans - providing all the key constituents required for life.

BBC: NEWS | Science/Nature | Earth-like planets may be common

Like phone books, we used to have immutable facts all compiled in Encyclopedia Britannica: 9 planets in our solar system, the Soviet Union, and avoid alcohol.

FORBES: When facts change fast, what should our kids be learning?

Small, rocky planets are the hardest of all to detect, but they are also the ones astrobiologists would most like to find.

ECONOMIST: A roadmap for planet-hunting