Richest planetary system discovered

Astronomers using ESO instruments have discovered a remarkable extrasolar planetary system that has some striking similarities to our own Solar System. At least five planets are orbiting the Sun-like star HD 10180, and the regular pattern of their orbits is similar to that observed for our neighbouring planets. One of the new extrasolar worlds could be only 1.4 times the mass of the Earth, making it the least massive exoplanet ever found. This video podcast explains how these faraway planets were detected and exactly what we know about them.