Life Friendly worlds in the universe probably already existed before than previously thought. An international team of researchers has discovered even same five planets orbiting a very old star. At 11.2 billion years ago, the planetary system around the star Kepler-444 is almost two and a half times as old as our solar system – and the oldest known, contains the planet of Earth-like size, the scientists write in the journal “Astrophysical Journal” .

With measured data of the space telescope “Kepler” the researchers discovered under the direction of the University of Birmingham in the planetary system. It to mute like a distant issue of our own inner solar system with the four planets Mercury, Venus, Earth and Mars. However orbiting Kepler-444 in the constellation Lyra even five small planets whose sizes are respectively between those of Mercury and Venus.
Oscillations reveal the star

For his analysis, the researchers made use of asteroseismology: They observed the oscillations of the star Kepler-444, produced by sound waves in its interior. “The vibrations cause tiny variations in the brightness of the light that shines the star into space,” says Saskia Hekker from the Max Planck Institute for Solar System Research in Göttingen. “You see we can diameter, mass and age of the star.”

In a second step, the astronomers felt the planets around the distant star. When viewed from Earth, an exoplanet passes in front of his star, he covers it in part and attenuates its light. From this, the size ratio between planet and star charge. The five exoplanets orbit Kepler-444 A are less than ten days and at a distance of less than a tenth of the distance between Earth and the sun.

“The new discovery has far-reaching consequences for our present picture of the universe,” says Tiago Campante, who led the study. The finding demonstrates that have occurred during much of the about 13.8 for billions of years of Earth-like planets history of the universe size.