In the quest for alien worlds, a team of Swiss, French and Portuguese astronomers have found a most remarkable system. They have discovered the most Earth-like planet outside our solar system to date, an exoplanet possibly having liquid water on its surface, and with a radius only 50% larger than the Earth. The system is moreover in our galactic neighborhood, located only about 20 light years from us. The discovery was made at the Isolacia Observatory in Chile. We have discovered a very low mass planet. In fact, it is the lowest mass ever discovered. It's only five times the mass of the Earth. This planet is probably a rocky planet, maybe 50% larger than the Earth for a very low mass planet orbiting the star with a period of 13 days. The planet completes a full orbit in 13 days. It is 14 times closer to its star than the Earth is from the Sun. However, because its host star is a red dwarf, the planet nevertheless lies in the habitable zone, the region around a star where water could be liquid. This planet is very exciting because at the distance of the planet from the star, we expect water to be present on the surface of the planet. And when you speak about water, you miss people's life. In fact, what the astronomers have unveiled is a complex system of three low mass planets. The first one, a 15 Earth mass planet, was discovered by the same team two years ago and orbits the star in five days. The second one is the five Earth mass planet in the habitable zone. And a third planet has also been detected. With a mass of eight times the Earth, it lies further out and takes 84 days to complete a full orbit. The system is also very interesting because the central star lies very close to us. In the galaxy, most of the stars are very low mass objects. In fact, as a star we are discussing, it's only one third of the mass of the Sun and it's one of the closest neighbor. It's only about 20 lighters from us. Because such planets are small and hidden in the glare of the star, it is very difficult to see them directly. To detect them, astronomers rely on indirect techniques, the most successful one being the radial velocity method. A planet in orbit around a star will show its presence by pulling the star in different directions, thereby changing its measured velocity in a very regular way. However, these changes are tiny of the order of a few meters per second and the most precise measuring machines are necessary. To make this incredible discovery, the astronomers used one of Esos telescopes, the 3.6 meter telescope located at La Sia in Chile. Attached to this telescope is the Harps spectrograph that can measure velocities with a precision better than 1 meter per second. These detections were made possible thanks to measurement obtained with Harps. The instrument that is presently the most precise one in the world to measure the radial velocity of stars. With this instrument, we already have detected 11 among the third working lightest known planets. The newly found super-earth will certainly attract a great deal of attention, especially from space-based astronomy missions that will look for life in the universe. Meanwhile, however, the astronomers do not plan to rest and have other ambitious goals. Personally, we are still not at the limit of the possibility of Harps, so I can anticipate that we have the possibility to still detect more smaller planets, maybe two Earth's mass and so on. And this is very challenging goal.