Using the HARPS instrument at the ESO La Silla Observatory, European astronomers have found a system of three super-Earths around the star HD 40307 - a breakthrough in the field of extra-solar planets. The astronomers also counted a total of 45 candidate planets with a mass below 30 Earth masses and an orbital period shorter than 50 days. This implies that one solar-like star out of three harbors such planets.

The three super-Earths orbit around a rather normal star, which is slightly less massive than Earth's Sun, and is located 42 light-years away. "Does every single star harbor planets and, if yes, how many?" wonders planet hunter Michel Mayor from Geneva Observatory. "We may not yet know the answer but we are making huge progress towards it." Current statistics show that about one out of 14 stars harbors this kind of planet.

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